[ { "sku": "HK0306FT2", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 3, "D_mm": 6.5, "B_mm": 6, "seal_type": "open", "dynamic_load_kN": 0.925, "static_load_kN": 0.565, "fatigue_load_limit_kN": 0.069, "limiting_speed_rpm": 33000, "speed_oil_rpm": 50000, "weight_g": 1, "manufacturer_designation": "HK0306FT2", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0306FT2" ], "naming_rule_text": "HK0306FT2 is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 3 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 6.5 mm and the width is 6 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. At this miniature shaft size the cup wall is fractions of a millimetre thick, so handling cleanliness and housing-bore accuracy matter more than the paper load rating. Automotive steering-column and pedal-box pivots use this size, where the cup is pressed into a sheet-metal bracket and the shaft sees only slow, heavily loaded oscillation. Never re-grease through a drilled hole in the housing wall without a vent path: pressure builds behind the cup, blows grease past the rollers, and starves the bearing while the housing looks full.", "applications": [ "small appliance gear drives", "instrument and meter linkages", "model and hobby drive trains", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "At a 3 mm shaft diameter the cup wall of HK0306FT2 is extremely thin; inspect for transportation dents before pressing in, and deburr the housing bore edge or the cup will score and split on entry.", "The cage in HK0306FT2 spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 3 mm.", "The 6 mm narrow section of HK0306FT2 is the compact option at 3 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 3×6.5 mm envelope.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell." ], "faq": [ { "q": "What are the dimensions of a HK0306FT2 needle roller bearing?", "a": "A HK0306FT2 drawn-cup needle roller bearing has a 3 mm shaft diameter (Fw, under-roller diameter), 6.5 mm outside diameter and 6 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0306FT2 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0306FT2, Fw = 3 mm, so the shaft must be machined to 3 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0306FT2 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0306FT2 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK0306FT2 retained in the housing?", "a": "The thin-walled drawn cup of HK0306FT2 is press-fitted into a 6.5 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0408FT2", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 4, "D_mm": 8, "B_mm": 8, "seal_type": "open", "dynamic_load_kN": 1.77, "static_load_kN": 1.27, "fatigue_load_limit_kN": 0.155, "limiting_speed_rpm": 30000, "speed_oil_rpm": 45000, "weight_g": 2, "manufacturer_designation": "HK0408FT2", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0408FT2" ], "naming_rule_text": "NTN HK0408FT2 belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 4 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 8 mm outside and 8 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. At this miniature shaft size the cup wall is fractions of a millimetre thick, so handling cleanliness and housing-bore accuracy matter more than the paper load rating. Small compressor crankshafts and refrigeration equipment fit this size on the eccentric pin, where the housing bore is finish-bored in the same setup as the main bearing seats. Where the housing is a welded fabrication, finish-bore the seat after all welding and stress-relief is complete — pressing the cup into a distorted, as-welded bore guarantees early spalling.", "applications": [ "small appliance gear drives", "instrument and meter linkages", "model and hobby drive trains", "reciprocating or oscillating motion where the rollers never complete a full revolution" ], "failure_modes": [ "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed" ], "pitfalls": [ "At a 4 mm shaft diameter the cup wall of HK0408FT2 is extremely thin; inspect for transportation dents before pressing in, and deburr the housing bore edge or the cup will score and split on entry.", "The cage in HK0408FT2 spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 4 mm.", "The 8 mm narrow section of HK0408FT2 is the compact option at 4 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 4×8 mm envelope.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell." ], "faq": [ { "q": "What are the dimensions of a HK0408FT2 needle roller bearing?", "a": "A HK0408FT2 drawn-cup needle roller bearing has a 4 mm shaft diameter (Fw, under-roller diameter), 8 mm outside diameter and 8 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0408FT2 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0408FT2, Fw = 4 mm, so the shaft must be machined to 4 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0408FT2 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0408FT2 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK0408FT2 retained in the housing?", "a": "The thin-walled drawn cup of HK0408FT2 is press-fitted into a 8 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0509FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 5, "D_mm": 9, "B_mm": 9, "seal_type": "open", "dynamic_load_kN": 2.45, "static_load_kN": 1.99, "fatigue_load_limit_kN": 0.243, "limiting_speed_rpm": 27000, "speed_oil_rpm": 40000, "weight_g": 2, "manufacturer_designation": "HK0509FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0509FM" ], "naming_rule_text": "HK0509FM is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 5 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 9 mm and the width is 9 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. At this miniature shaft size the cup wall is fractions of a millimetre thick, so handling cleanliness and housing-bore accuracy matter more than the paper load rating. Conveyor and packaging-machinery builders choose this size for idler and tensioner rollers: the open ends accept a grease fill at assembly and the cup survives the life of the roller shell. When the housing is aluminium or magnesium, press this cup into a steel insert rather than the bare casting — differential thermal expansion will walk the cup out of a soft bore at operating temperature.", "applications": [ "office machine and printer mechanisms", "small appliance gear drives", "instrument and meter linkages", "heavily loaded slow pivots where static rating, not dynamic life, governs the choice" ], "failure_modes": [ "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path" ], "pitfalls": [ "At a 5 mm shaft diameter the cup wall of HK0509FM is extremely thin; inspect for transportation dents before pressing in, and deburr the housing bore edge or the cup will score and split on entry.", "The cage in HK0509FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 5 mm.", "The 9 mm narrow section of HK0509FM is the compact option at 5 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 5×9 mm envelope.", "HK0509FM runs directly on the shaft: the 5 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK0509FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty." ], "faq": [ { "q": "What are the dimensions of a HK0509FM needle roller bearing?", "a": "A HK0509FM drawn-cup needle roller bearing has a 5 mm shaft diameter (Fw, under-roller diameter), 9 mm outside diameter and 9 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0509FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0509FM, Fw = 5 mm, so the shaft must be machined to 5 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0509FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0509FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK0509FM retained in the housing?", "a": "The thin-walled drawn cup of HK0509FM is press-fitted into a 9 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What duty conditions suit a HK0509FM drawn-cup bearing?", "a": "HK0509FM is typically specified for reciprocating or oscillating motion where the rollers never complete a full revolution; match the grease/oil speed limits (27000/40000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0609FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 6, "D_mm": 10, "B_mm": 9, "seal_type": "open", "dynamic_load_kN": 2.92, "static_load_kN": 2.59, "fatigue_load_limit_kN": 0.315, "limiting_speed_rpm": 25000, "speed_oil_rpm": 37000, "weight_g": 2, "manufacturer_designation": "HK0609FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0609FM" ], "naming_rule_text": "HK0609FM is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 6 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 10 mm and the width is 9 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. At this miniature shaft size the cup wall is fractions of a millimetre thick, so handling cleanliness and housing-bore accuracy matter more than the paper load rating. Garden machinery and small outboard engines fit this size in the crankcase web: the thin cup keeps the crank web narrow while still carrying the combustion pulses through the connecting-rod small end. Use a mandrel with a lead chamfer that matches the cup bore when pressing this size home; a flat-faced drift can catch the roller cage and distort the shell before it is fully seated.", "applications": [ "micro gearbox and servo output shafts", "office machine and printer mechanisms", "small appliance gear drives", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "At a 6 mm shaft diameter the cup wall of HK0609FM is extremely thin; inspect for transportation dents before pressing in, and deburr the housing bore edge or the cup will score and split on entry.", "The cage in HK0609FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 6 mm.", "The 9 mm narrow section of HK0609FM is the compact option at 6 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 6×10 mm envelope.", "The HK0609FM drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life." ], "faq": [ { "q": "What are the dimensions of a HK0609FM needle roller bearing?", "a": "A HK0609FM drawn-cup needle roller bearing has a 6 mm shaft diameter (Fw, under-roller diameter), 10 mm outside diameter and 9 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0609FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0609FM, Fw = 6 mm, so the shaft must be machined to 6 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0609FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0609FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK0609FM retained in the housing?", "a": "The thin-walled drawn cup of HK0609FM is press-fitted into a 10 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0709FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 7, "D_mm": 11, "B_mm": 9, "seal_type": "open", "dynamic_load_kN": 3.15, "static_load_kN": 2.93, "fatigue_load_limit_kN": 0.355, "limiting_speed_rpm": 23000, "speed_oil_rpm": 34000, "weight_g": 2, "manufacturer_designation": "HK0709FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0709FM" ], "naming_rule_text": "NTN HK0709FM belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 7 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 11 mm outside and 9 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. In this size range the drawn cup gives a far smaller radial section than any machined-ring needle bearing of the same shaft, which is why it dominates in compact transmissions. Small compressor crankshafts and refrigeration equipment fit this size on the eccentric pin, where the housing bore is finish-bored in the same setup as the main bearing seats. Where the housing is a welded fabrication, finish-bore the seat after all welding and stress-relief is complete — pressing the cup into a distorted, as-welded bore guarantees early spalling.", "applications": [ "automotive accessory drives", "lawn and garden equipment spindles", "motorcycle and scooter transmissions", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "At a 7 mm shaft diameter, shaft surface finish is critical for HK0709FM: grinding marks, corrosion pits or chrome flaking on the journal will fluke the rollers within hours — polish or replace a suspect shaft.", "The cage in HK0709FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 7 mm.", "The 9 mm narrow section of HK0709FM is the compact option at 7 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 7×11 mm envelope.", "The open ends of HK0709FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty." ], "faq": [ { "q": "What are the dimensions of a HK0709FM needle roller bearing?", "a": "A HK0709FM drawn-cup needle roller bearing has a 7 mm shaft diameter (Fw, under-roller diameter), 11 mm outside diameter and 9 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0709FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0709FM, Fw = 7 mm, so the shaft must be machined to 7 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0709FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0709FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK0709FM retained in the housing?", "a": "The thin-walled drawn cup of HK0709FM is press-fitted into a 11 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0810FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 8, "D_mm": 12, "B_mm": 10, "seal_type": "open", "dynamic_load_kN": 3.85, "static_load_kN": 3.95, "fatigue_load_limit_kN": 0.48, "limiting_speed_rpm": 20000, "speed_oil_rpm": 30000, "weight_g": 3, "manufacturer_designation": "HK0810FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0810FM", "HK0810FM+IR5x8x12" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK0810FM is built around a thin hardened steel cup.Its printed envelope — 8 mm under-roller diameter, 12 mm outside diameter, 10 mm width — is fixed by ISO 3245; the 8 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. In this size range the drawn cup gives a far smaller radial section than any machined-ring needle bearing of the same shaft, which is why it dominates in compact transmissions. Conveyor and packaging-machinery builders choose this size for idler and tensioner rollers: the open ends accept a grease fill at assembly and the cup survives the life of the roller shell. When the housing is aluminium or magnesium, press this cup into a steel insert rather than the bare casting — differential thermal expansion will walk the cup out of a soft bore at operating temperature.", "applications": [ "lawn and garden equipment spindles", "motorcycle and scooter transmissions", "two-stroke engine crank and piston pins", "compact linkages where the cup doubles as both bearing and structural spacer" ], "failure_modes": [ "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection" ], "pitfalls": [ "Needle rollers tolerate almost no misalignment; if the 12 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "At a 8 mm shaft diameter, shaft surface finish is critical for HK0810FM: grinding marks, corrosion pits or chrome flaking on the journal will fluke the rollers within hours — polish or replace a suspect shaft.", "The cage in HK0810FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 8 mm.", "The 10 mm narrow section of HK0810FM is the compact option at 8 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 8×12 mm envelope." ], "faq": [ { "q": "Does HK0810FM need a hardened shaft?", "a": "Either the 8 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR5x8x12) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK0810FM drawn-cup bearing?", "a": "HK0810FM is typically specified for lightly loaded high-speed idler positions where roller skidding must be watched; match the grease/oil speed limits (20000/30000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK0810FM needle roller bearing?", "a": "A HK0810FM drawn-cup needle roller bearing has a 8 mm shaft diameter (Fw, under-roller diameter), 12 mm outside diameter and 10 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0810FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0810FM, Fw = 8 mm, so the shaft must be machined to 8 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0810FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0810FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0910FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 9, "D_mm": 13, "B_mm": 10, "seal_type": "open", "dynamic_load_kN": 4.3, "static_load_kN": 4.65, "fatigue_load_limit_kN": 0.57, "limiting_speed_rpm": 18000, "speed_oil_rpm": 27000, "weight_g": 4, "manufacturer_designation": "HK0910FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0910FM", "HK0910FM+IR6x9x12" ], "naming_rule_text": "HK0910FM is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 9 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 13 mm and the width is 10 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. In this size range the drawn cup gives a far smaller radial section than any machined-ring needle bearing of the same shaft, which is why it dominates in compact transmissions. Garden machinery and small outboard engines fit this size in the crankcase web: the thin cup keeps the crank web narrow while still carrying the combustion pulses through the connecting-rod small end. Use a mandrel with a lead chamfer that matches the cup bore when pressing this size home; a flat-faced drift can catch the roller cage and distort the shell before it is fully seated.", "applications": [ "small hydraulic pump drives", "automotive accessory drives", "lawn and garden equipment spindles", "compact linkages where the cup doubles as both bearing and structural spacer" ], "failure_modes": [ "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection" ], "pitfalls": [ "At a 9 mm shaft diameter, shaft surface finish is critical for HK0910FM: grinding marks, corrosion pits or chrome flaking on the journal will fluke the rollers within hours — polish or replace a suspect shaft.", "The cage in HK0910FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 9 mm.", "The 10 mm narrow section of HK0910FM is the compact option at 9 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 9×13 mm envelope.", "Drawn-cup needle bearings carry radial load only: HK0910FM provides no axial shaft location — use separate thrust washers or a locating bearing for axial forces.", "The HK0910FM drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life." ], "faq": [ { "q": "What are the dimensions of a HK0910FM needle roller bearing?", "a": "A HK0910FM drawn-cup needle roller bearing has a 9 mm shaft diameter (Fw, under-roller diameter), 13 mm outside diameter and 10 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0910FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0910FM, Fw = 9 mm, so the shaft must be machined to 9 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0910FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0910FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK0910FM need a hardened shaft?", "a": "Either the 9 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR6x9x12) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK0910FM drawn-cup bearing?", "a": "HK0910FM is typically specified for lightly loaded high-speed idler positions where roller skidding must be watched; match the grease/oil speed limits (18000/27000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK0912F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 9, "D_mm": 13, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 5.4, "static_load_kN": 6.25, "fatigue_load_limit_kN": 0.765, "limiting_speed_rpm": 18000, "speed_oil_rpm": 27000, "weight_g": 4, "manufacturer_designation": "HK0912F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK0912F", "HK0912F+IR6x9x12" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK0912F is built around a thin hardened steel cup.Its printed envelope — 9 mm under-roller diameter, 13 mm outside diameter, 12 mm width — is fixed by ISO 3245; the 9 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "power tool gear reduction stages", "small hydraulic pump drives", "automotive accessory drives", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "The open ends of HK0912F retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "With no inner ring, HK0912F reads the 9 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK0912F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 9 mm.", "The 12 mm standard width of HK0912F is the general-purpose section at 9 mm shaft; wider HK variants in the same 9×13 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "HK0912F runs directly on the shaft: the 9 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead." ], "faq": [ { "q": "What duty conditions suit a HK0912F drawn-cup bearing?", "a": "HK0912F is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (18000/27000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK0912F needle roller bearing?", "a": "A HK0912F drawn-cup needle roller bearing has a 9 mm shaft diameter (Fw, under-roller diameter), 13 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK0912F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK0912F, Fw = 9 mm, so the shaft must be machined to 9 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK0912F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK0912F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK0912F need a hardened shaft?", "a": "Either the 9 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR6x9x12) so a standard unhardened shaft can be used." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1010FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 10, "D_mm": 14, "B_mm": 10, "seal_type": "open", "dynamic_load_kN": 4.5, "static_load_kN": 5.1, "fatigue_load_limit_kN": 0.62, "limiting_speed_rpm": 16000, "speed_oil_rpm": 24000, "weight_g": 4, "manufacturer_designation": "HK1010FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1010FM", "HK1010FM+IR7x10x10.5" ], "naming_rule_text": "In the HK-series (ISO 3245), HK1010FM is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 10 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 14 mm cup outside diameter and 10 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. Garden machinery and small outboard engines fit this size in the crankcase web: the thin cup keeps the crank web narrow while still carrying the combustion pulses through the connecting-rod small end. Use a mandrel with a lead chamfer that matches the cup bore when pressing this size home; a flat-faced drift can catch the roller cage and distort the shell before it is fully seated.", "applications": [ "automotive accessory drives", "lawn and garden equipment spindles", "motorcycle and scooter transmissions", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "The 10 mm narrow section of HK1010FM is the compact option at 10 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 10×14 mm envelope.", "The open ends of HK1010FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "With no inner ring, HK1010FM reads the 10 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK1010FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 10 mm." ], "faq": [ { "q": "Can a HK1010FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1010FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK1010FM need a hardened shaft?", "a": "Either the 10 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR7x10x10.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1010FM needle roller bearing?", "a": "A HK1010FM drawn-cup needle roller bearing has a 10 mm shaft diameter (Fw, under-roller diameter), 14 mm outside diameter and 10 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1010FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1010FM, Fw = 10 mm, so the shaft must be machined to 10 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1012F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 10, "D_mm": 14, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 5.65, "static_load_kN": 6.8, "fatigue_load_limit_kN": 0.83, "limiting_speed_rpm": 16000, "speed_oil_rpm": 24000, "weight_g": 4, "manufacturer_designation": "HK1012F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1012F", "HK1012F+IR7x10x16" ], "naming_rule_text": "HK1012F is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 10 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 14 mm and the width is 12 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. Office automation equipment — printers, copiers, paper feeders — uses this size in the transport rollers, where the open ends are enclosed by the chassis and relubrication is never planned. For vertical shafts, arrange the housing so the open end of the cup faces up or provides a grease reservoir below — gravity drains lubricant away from the roller set otherwise.", "applications": [ "two-stroke engine crank and piston pins", "power tool gear reduction stages", "small hydraulic pump drives", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "The HK1012F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "With no inner ring, HK1012F reads the 10 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK1012F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 10 mm.", "The 12 mm standard width of HK1012F is the general-purpose section at 10 mm shaft; wider HK variants in the same 10×14 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1012F need a hardened shaft?", "a": "Either the 10 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR7x10x16) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1012F needle roller bearing?", "a": "A HK1012F drawn-cup needle roller bearing has a 10 mm shaft diameter (Fw, under-roller diameter), 14 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1012F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1012F, Fw = 10 mm, so the shaft must be machined to 10 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1012F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1012F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1015F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 10, "D_mm": 14, "B_mm": 15, "seal_type": "open", "dynamic_load_kN": 7.25, "static_load_kN": 9.4, "fatigue_load_limit_kN": 1.14, "limiting_speed_rpm": 16000, "speed_oil_rpm": 24000, "weight_g": 6, "manufacturer_designation": "HK1015F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1015F", "HK1015F+IR7x10x16" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK1015F is built around a thin hardened steel cup.Its printed envelope — 10 mm under-roller diameter, 14 mm outside diameter, 15 mm width — is fixed by ISO 3245; the 10 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. Industrial sewing machines and textile equipment run this size on their shuttle and needle-bar drive shafts, where the compact radial section keeps the arm profile slim. Shaft tolerance for this size is h5 or j5: the roller complement needs a controlled radial clearance, and a shaft ground to general-purpose tolerances can leave the bearing either slack or pinched.", "applications": [ "automotive accessory drives", "lawn and garden equipment spindles", "motorcycle and scooter transmissions", "shock-loaded start-stop service such as clutch and kick-starter mechanisms" ], "failure_modes": [ "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell" ], "pitfalls": [ "The HK1015F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "With no inner ring, HK1015F reads the 10 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK1015F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 10 mm.", "The 15 mm standard width of HK1015F is the general-purpose section at 10 mm shaft; wider HK variants in the same 10×14 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Drawn-cup needle bearings carry radial load only: HK1015F provides no axial shaft location — use separate thrust washers or a locating bearing for axial forces." ], "faq": [ { "q": "What duty conditions suit a HK1015F drawn-cup bearing?", "a": "HK1015F is typically specified for dirty environments where the open ends rely entirely on the housing seals; match the grease/oil speed limits (16000/24000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK1015F needle roller bearing?", "a": "A HK1015F drawn-cup needle roller bearing has a 10 mm shaft diameter (Fw, under-roller diameter), 14 mm outside diameter and 15 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1015F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1015F, Fw = 10 mm, so the shaft must be machined to 10 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1015F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1015F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK1015F need a hardened shaft?", "a": "Either the 10 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR7x10x16) so a standard unhardened shaft can be used." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1210FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 12, "D_mm": 16, "B_mm": 10, "seal_type": "open", "dynamic_load_kN": 5.05, "static_load_kN": 6.25, "fatigue_load_limit_kN": 0.76, "limiting_speed_rpm": 13000, "speed_oil_rpm": 20000, "weight_g": 5, "manufacturer_designation": "HK1210FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1210FM", "HK1210FM+IR8x12x10.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK1210FM is built around a thin hardened steel cup.Its printed envelope — 12 mm under-roller diameter, 16 mm outside diameter, 10 mm width — is fixed by ISO 3245; the 12 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. Industrial sewing machines and textile equipment run this size on their shuttle and needle-bar drive shafts, where the compact radial section keeps the arm profile slim. Shaft tolerance for this size is h5 or j5: the roller complement needs a controlled radial clearance, and a shaft ground to general-purpose tolerances can leave the bearing either slack or pinched.", "applications": [ "two-stroke engine crank and piston pins", "power tool gear reduction stages", "small hydraulic pump drives", "heavily loaded slow pivots where static rating, not dynamic life, governs the choice" ], "failure_modes": [ "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path" ], "pitfalls": [ "HK1210FM runs directly on the shaft: the 12 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK1210FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "With no inner ring, HK1210FM reads the 12 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK1210FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 12 mm.", "The 10 mm narrow section of HK1210FM is the compact option at 12 mm shaft: load capacity is limited by the short roller length, so verify the required rating before choosing it over a wider HK variant in the same 12×16 mm envelope." ], "faq": [ { "q": "Does HK1210FM need a hardened shaft?", "a": "Either the 12 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR8x12x10.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK1210FM drawn-cup bearing?", "a": "HK1210FM is typically specified for reciprocating or oscillating motion where the rollers never complete a full revolution; match the grease/oil speed limits (13000/20000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK1210FM needle roller bearing?", "a": "A HK1210FM drawn-cup needle roller bearing has a 12 mm shaft diameter (Fw, under-roller diameter), 16 mm outside diameter and 10 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1210FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1210FM, Fw = 12 mm, so the shaft must be machined to 12 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1210FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1210FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1212FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 12, "D_mm": 18, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 6.6, "static_load_kN": 7.3, "fatigue_load_limit_kN": 0.89, "limiting_speed_rpm": 13000, "speed_oil_rpm": 20000, "weight_g": 9, "manufacturer_designation": "HK1212FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1212FM", "HK1212FM+IR8x12x12.5" ], "naming_rule_text": "NTN HK1212FM belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 12 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 18 mm outside and 12 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "small hydraulic pump drives", "automotive accessory drives", "lawn and garden equipment spindles", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "The cage in HK1212FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 12 mm.", "The 12 mm standard width of HK1212FM is the general-purpose section at 12 mm shaft; wider HK variants in the same 12×18 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "With no inner ring, HK1212FM reads the 12 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations." ], "faq": [ { "q": "What does Fw mean on a HK1212FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1212FM, Fw = 12 mm, so the shaft must be machined to 12 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1212FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1212FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK1212FM need a hardened shaft?", "a": "Either the 12 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR8x12x12.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1212FM needle roller bearing?", "a": "A HK1212FM drawn-cup needle roller bearing has a 12 mm shaft diameter (Fw, under-roller diameter), 18 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1312FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 13, "D_mm": 19, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 6.95, "static_load_kN": 7.9, "fatigue_load_limit_kN": 0.965, "limiting_speed_rpm": 12000, "speed_oil_rpm": 18000, "weight_g": 10, "manufacturer_designation": "HK1312FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1312FM", "HK1312FM+IR10x13x12.5" ], "naming_rule_text": "NTN HK1312FM belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 13 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 19 mm outside and 12 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. This cup size is common in power-tool intermediate shafts — drills, saws, grinders — where the gearbox casing is magnesium or aluminium and the cup is pressed into a steel insert. If the shaft sees axial float, allow for it in the housing width — the cup cannot guide the shaft axially, and a shaft that walks will eventually hammer the open end of the shell.", "applications": [ "power tool gear reduction stages", "small hydraulic pump drives", "automotive accessory drives", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "HK1312FM runs directly on the shaft: the 13 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK1312FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "With no inner ring, HK1312FM reads the 13 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK1312FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 13 mm.", "The 12 mm standard width of HK1312FM is the general-purpose section at 13 mm shaft; wider HK variants in the same 13×19 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1312FM need a hardened shaft?", "a": "Either the 13 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR10x13x12.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK1312FM drawn-cup bearing?", "a": "HK1312FM is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (12000/18000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK1312FM needle roller bearing?", "a": "A HK1312FM drawn-cup needle roller bearing has a 13 mm shaft diameter (Fw, under-roller diameter), 19 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1312FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1312FM, Fw = 13 mm, so the shaft must be machined to 13 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1312FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1312FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1412FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 14, "D_mm": 20, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 7.2, "static_load_kN": 8.5, "fatigue_load_limit_kN": 1.04, "limiting_speed_rpm": 11000, "speed_oil_rpm": 17000, "weight_g": 11, "manufacturer_designation": "HK1412FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1412FM", "HK1412FM+IR10x14x13" ], "naming_rule_text": "The NTN HK1412FM — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 14 mm is Fw, the under-roller (shaft journal) diameter; 20 mm and 12 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. This is the classic two-wheeler and small-engine size class: the cup replaces a bulky machined bearing and lets the gearbox casing shrink around it. Compact hydraulic gear pumps use this size on their drive shafts: the pump housing is machined once, the cup is pressed home, and the shaft runs directly on the rollers for the life of the unit. For oscillating service, pack this size with a high-tackiness grease and re-lubricate at short intervals: the rollers do not complete a full revolution, so the same contact patch carries the load cycle after cycle.", "applications": [ "motorcycle and scooter transmissions", "two-stroke engine crank and piston pins", "power tool gear reduction stages", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "With no inner ring, HK1412FM reads the 14 mm shaft surface as its raceway: hardness 58–64 HRC and a ground finish are prerequisites, not recommendations.", "The cage in HK1412FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 14 mm.", "The 12 mm standard width of HK1412FM is the general-purpose section at 14 mm shaft; wider HK variants in the same 14×20 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Needle rollers tolerate almost no misalignment; if the 20 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell." ], "faq": [ { "q": "What are the dimensions of a HK1412FM needle roller bearing?", "a": "A HK1412FM drawn-cup needle roller bearing has a 14 mm shaft diameter (Fw, under-roller diameter), 20 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1412FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1412FM, Fw = 14 mm, so the shaft must be machined to 14 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1412FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1412FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK1412FM need a hardened shaft?", "a": "Either the 14 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR10x14x13) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK1412FM drawn-cup bearing?", "a": "HK1412FM is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (11000/17000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1416F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 14, "D_mm": 20, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 10.3, "static_load_kN": 13.4, "fatigue_load_limit_kN": 1.64, "limiting_speed_rpm": 11000, "speed_oil_rpm": 17000, "weight_g": 15, "manufacturer_designation": "HK1416F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1416F" ], "naming_rule_text": "NTN HK1416F belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 14 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 20 mm outside and 16 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Drawn cups in this class are the default compact radial bearing in motorcycle and power-tool gearboxes, where housing space is the binding constraint. Office automation equipment — printers, copiers, paper feeders — uses this size in the transport rollers, where the open ends are enclosed by the chassis and relubrication is never planned. For vertical shafts, arrange the housing so the open end of the cup faces up or provides a grease reservoir below — gravity drains lubricant away from the roller set otherwise.", "applications": [ "small hydraulic pump drives", "automotive accessory drives", "lawn and garden equipment spindles", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "The rollers of HK1416F run directly on the 14 mm journal: any score mark, rust pit or plating flake on that surface becomes a raceway defect — dress or replace a marginal shaft.", "The cage in HK1416F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 14 mm.", "The 16 mm standard width of HK1416F is the general-purpose section at 14 mm shaft; wider HK variants in the same 14×20 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "How is a HK1416F retained in the housing?", "a": "The thin-walled drawn cup of HK1416F is press-fitted into a 20 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What are the dimensions of a HK1416F needle roller bearing?", "a": "A HK1416F drawn-cup needle roller bearing has a 14 mm shaft diameter (Fw, under-roller diameter), 20 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1416F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1416F, Fw = 14 mm, so the shaft must be machined to 14 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1416F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1416F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1512FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 15, "D_mm": 21, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 7.5, "static_load_kN": 9.1, "fatigue_load_limit_kN": 1.11, "limiting_speed_rpm": 11000, "speed_oil_rpm": 16000, "weight_g": 11, "manufacturer_designation": "HK1512FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1512FM", "HK1512FM+IR12x15x12.5" ], "naming_rule_text": "The NTN HK1512FM — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 15 mm is Fw, the under-roller (shaft journal) diameter; 21 mm and 12 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Conveyor and packaging-machinery builders choose this size for idler and tensioner rollers: the open ends accept a grease fill at assembly and the cup survives the life of the roller shell. When the housing is aluminium or magnesium, press this cup into a steel insert rather than the bare casting — differential thermal expansion will walk the cup out of a soft bore at operating temperature.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "The open ends of HK1512FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "Mid-size cups like HK1512FM (15 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK1512FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 15 mm.", "The 12 mm standard width of HK1512FM is the general-purpose section at 15 mm shaft; wider HK variants in the same 15×21 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1512FM need a hardened shaft?", "a": "Either the 15 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR12x15x12.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1512FM needle roller bearing?", "a": "A HK1512FM drawn-cup needle roller bearing has a 15 mm shaft diameter (Fw, under-roller diameter), 21 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1512FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1512FM, Fw = 15 mm, so the shaft must be machined to 15 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1512FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1512FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1516F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 15, "D_mm": 21, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 10.7, "static_load_kN": 14.4, "fatigue_load_limit_kN": 1.75, "limiting_speed_rpm": 11000, "speed_oil_rpm": 16000, "weight_g": 15, "manufacturer_designation": "HK1516F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1516F", "HK1516F+IR12x15x16.5" ], "naming_rule_text": "The NTN HK1516F — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 15 mm is Fw, the under-roller (shaft journal) diameter; 21 mm and 16 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Automotive gearbox designers default to this class when the radial envelope is fixed: the cup keeps the casing compact without giving up the required rating. You will find this cup size inside small two-stroke crankcases, supporting the small-end of the connecting rod where the housing is split and the bearing is pressed in before the case halves close. If the shaft cannot be hardened, press the matching IR inner ring onto it first; the ring gives the rollers a hardened, ground raceway and lets you keep a soft shaft for assembly reasons.", "applications": [ "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "compressor crankshaft supports", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "The HK1516F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Before pressing HK1516F in, verify the 15 mm housing seat is still round — extracting the old cup often pulls the bore, and the new thin shell will conform to any distortion.", "The cage in HK1516F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 15 mm.", "The 16 mm standard width of HK1516F is the general-purpose section at 15 mm shaft; wider HK variants in the same 15×21 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1516F need a hardened shaft?", "a": "Either the 15 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR12x15x16.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1516F needle roller bearing?", "a": "A HK1516F drawn-cup needle roller bearing has a 15 mm shaft diameter (Fw, under-roller diameter), 21 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1516F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1516F, Fw = 15 mm, so the shaft must be machined to 15 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1516F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1516F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1522ZWFD", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 15, "D_mm": 21, "B_mm": 22, "seal_type": "open", "dynamic_load_kN": 12.9, "static_load_kN": 18.2, "fatigue_load_limit_kN": 2.22, "limiting_speed_rpm": 11000, "speed_oil_rpm": 16000, "weight_g": 20, "manufacturer_designation": "HK1522ZWFD", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1522ZWFD", "HK1522ZWFD+IR12x15x22.5" ], "naming_rule_text": "NTN HK1522ZWFD belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 15 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 21 mm outside and 22 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The ZW suffix marks two roller rows in the same cup, roughly doubling the dynamic rating of the width-equivalent single-row version at the cost of the extra width. In this mid size range the HK cup is the standard compact radial bearing choice across automotive and industrial gearboxes. Automotive steering-column and pedal-box pivots use this size, where the cup is pressed into a sheet-metal bracket and the shaft sees only slow, heavily loaded oscillation. Never re-grease through a drilled hole in the housing wall without a vent path: pressure builds behind the cup, blows grease past the rollers, and starves the bearing while the housing looks full.", "applications": [ "automotive manual transmission gear sets", "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "reciprocating or oscillating motion where the rollers never complete a full revolution" ], "failure_modes": [ "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed" ], "pitfalls": [ "The 22 mm wide section of HK1522ZWFD gains rating through longer rollers at 15 mm shaft; confirm the housing width accepts 22 mm — it will not drop into a seat machined for the 15×21 mm narrow variant.", "The open ends of HK1522ZWFD retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "At a 15 mm shaft diameter, check housing bore roundness after previous bearing removal for HK1522ZWFD; a pulled or scored seat must be re-machined or sleeved before the new cup goes in.", "The two roller rows in HK1522ZWFD share one cup: any shaft bending or housing-bore taper loads one row ahead of the other, so hold the 21 mm seat straight over the full 22 mm width and keep shaft deflection minimal." ], "faq": [ { "q": "Can a HK1522ZWFD needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1522ZWFD carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK1522ZWFD need a hardened shaft?", "a": "Either the 15 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR12x15x22.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1522ZWFD needle roller bearing?", "a": "A HK1522ZWFD drawn-cup needle roller bearing has a 15 mm shaft diameter (Fw, under-roller diameter), 21 mm outside diameter and 22 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1522ZWFD drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1522ZWFD, Fw = 15 mm, so the shaft must be machined to 15 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1612FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 16, "D_mm": 22, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 7.75, "static_load_kN": 9.7, "fatigue_load_limit_kN": 1.18, "limiting_speed_rpm": 10000, "speed_oil_rpm": 15000, "weight_g": 12, "manufacturer_designation": "HK1612FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1612FM", "HK1612FM+IR12x16x13" ], "naming_rule_text": "In the HK-series (ISO 3245), HK1612FM is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 16 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 22 mm cup outside diameter and 12 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Garden machinery and small outboard engines fit this size in the crankcase web: the thin cup keeps the crank web narrow while still carrying the combustion pulses through the connecting-rod small end. Use a mandrel with a lead chamfer that matches the cup bore when pressing this size home; a flat-faced drift can catch the roller cage and distort the shell before it is fully seated.", "applications": [ "compressor crankshaft supports", "agricultural machinery PTO drives", "universal joint and steering pivots", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Mid-size cups like HK1612FM (16 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK1612FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 16 mm.", "The 12 mm standard width of HK1612FM is the general-purpose section at 16 mm shaft; wider HK variants in the same 16×22 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1612FM need a hardened shaft?", "a": "Either the 16 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR12x16x13) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1612FM needle roller bearing?", "a": "A HK1612FM drawn-cup needle roller bearing has a 16 mm shaft diameter (Fw, under-roller diameter), 22 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1612FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1612FM, Fw = 16 mm, so the shaft must be machined to 16 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1612FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1612FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1616F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 16, "D_mm": 22, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 11.1, "static_load_kN": 15.3, "fatigue_load_limit_kN": 1.87, "limiting_speed_rpm": 10000, "speed_oil_rpm": 15000, "weight_g": 16, "manufacturer_designation": "HK1616F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1616F", "HK1616F+IR12x16x20" ], "naming_rule_text": "In the HK-series (ISO 3245), HK1616F is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 16 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 22 mm cup outside diameter and 16 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. In this mid size range the HK cup is the standard compact radial bearing choice across automotive and industrial gearboxes. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "The open ends of HK1616F retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "At a 16 mm shaft diameter, check housing bore roundness after previous bearing removal for HK1616F; a pulled or scored seat must be re-machined or sleeved before the new cup goes in.", "The cage in HK1616F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 16 mm.", "The 16 mm standard width of HK1616F is the general-purpose section at 16 mm shaft; wider HK variants in the same 16×22 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1616F need a hardened shaft?", "a": "Either the 16 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR12x16x20) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1616F needle roller bearing?", "a": "A HK1616F drawn-cup needle roller bearing has a 16 mm shaft diameter (Fw, under-roller diameter), 22 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1616F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1616F, Fw = 16 mm, so the shaft must be machined to 16 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1616F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1616F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1622ZWFD", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 16, "D_mm": 22, "B_mm": 22, "seal_type": "open", "dynamic_load_kN": 13.3, "static_load_kN": 19.4, "fatigue_load_limit_kN": 2.37, "limiting_speed_rpm": 10000, "speed_oil_rpm": 15000, "weight_g": 22, "manufacturer_designation": "HK1622ZWFD", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1622ZWFD" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK1622ZWFD is built around a thin hardened steel cup.Its printed envelope — 16 mm under-roller diameter, 22 mm outside diameter, 22 mm width — is fixed by ISO 3245; the 16 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The ZW suffix marks two roller rows in the same cup, roughly doubling the dynamic rating of the width-equivalent single-row version at the cost of the extra width. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Small electric actuators and valve gear specify this size on the output shaft, where the gearmotor pinion needs support but the casting leaves no room for a machined ring. In dusty environments, place an external lip seal or felt washer immediately adjacent to the open cup end; the rollers have no defence against grit that migrates through the housing.", "applications": [ "compressor crankshaft supports", "agricultural machinery PTO drives", "universal joint and steering pivots", "shock-loaded start-stop service such as clutch and kick-starter mechanisms" ], "failure_modes": [ "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell" ], "pitfalls": [ "Mid-size cups like HK1622ZWFD (16 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The two roller rows in HK1622ZWFD share one cup: any shaft bending or housing-bore taper loads one row ahead of the other, so hold the 22 mm seat straight over the full 22 mm width and keep shaft deflection minimal.", "The 22 mm wide section of HK1622ZWFD gains rating through longer rollers at 16 mm shaft; confirm the housing width accepts 22 mm — it will not drop into a seat machined for the 16×22 mm narrow variant.", "HK1622ZWFD runs directly on the shaft: the 16 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK1622ZWFD retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty." ], "faq": [ { "q": "What are the dimensions of a HK1622ZWFD needle roller bearing?", "a": "A HK1622ZWFD drawn-cup needle roller bearing has a 16 mm shaft diameter (Fw, under-roller diameter), 22 mm outside diameter and 22 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1622ZWFD drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1622ZWFD, Fw = 16 mm, so the shaft must be machined to 16 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1622ZWFD needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1622ZWFD carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK1622ZWFD retained in the housing?", "a": "The thin-walled drawn cup of HK1622ZWFD is press-fitted into a 22 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What duty conditions suit a HK1622ZWFD drawn-cup bearing?", "a": "HK1622ZWFD is typically specified for dirty environments where the open ends rely entirely on the housing seals; match the grease/oil speed limits (10000/15000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1712FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 17, "D_mm": 23, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 8.05, "static_load_kN": 10.3, "fatigue_load_limit_kN": 1.26, "limiting_speed_rpm": 9500, "speed_oil_rpm": 14000, "weight_g": 12, "manufacturer_designation": "HK1712FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1712FM" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK1712FM is built around a thin hardened steel cup.Its printed envelope — 17 mm under-roller diameter, 23 mm outside diameter, 12 mm width — is fixed by ISO 3245; the 17 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Small compressor crankshafts and refrigeration equipment fit this size on the eccentric pin, where the housing bore is finish-bored in the same setup as the main bearing seats. Where the housing is a welded fabrication, finish-bore the seat after all welding and stress-relief is complete — pressing the cup into a distorted, as-welded bore guarantees early spalling.", "applications": [ "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "compressor crankshaft supports", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "The HK1712FM drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Mid-size cups like HK1712FM (17 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK1712FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 17 mm.", "The 12 mm standard width of HK1712FM is the general-purpose section at 17 mm shaft; wider HK variants in the same 17×23 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "How is a HK1712FM retained in the housing?", "a": "The thin-walled drawn cup of HK1712FM is press-fitted into a 23 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What are the dimensions of a HK1712FM needle roller bearing?", "a": "A HK1712FM drawn-cup needle roller bearing has a 17 mm shaft diameter (Fw, under-roller diameter), 23 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1712FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1712FM, Fw = 17 mm, so the shaft must be machined to 17 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1712FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1712FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1812FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 18, "D_mm": 24, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 8.3, "static_load_kN": 10.9, "fatigue_load_limit_kN": 1.33, "limiting_speed_rpm": 8500, "speed_oil_rpm": 13000, "weight_g": 13, "manufacturer_designation": "HK1812FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1812FM", "HK1812FM+IR15x18x12.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK1812FM is built around a thin hardened steel cup.Its printed envelope — 18 mm under-roller diameter, 24 mm outside diameter, 12 mm width — is fixed by ISO 3245; the 18 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Agricultural PTO shafts and small tractor linkages use this size at the pivot points: the cup is pressed into a welded eye and forgotten until the implement is overhauled. Mounting this size in a split housing needs the cup pressed into one half only, with the joint face relieved so the shell is not pinched when the case bolts come up to torque.", "applications": [ "automotive manual transmission gear sets", "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "shock-loaded start-stop service such as clutch and kick-starter mechanisms" ], "failure_modes": [ "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Mid-size cups like HK1812FM (18 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK1812FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 18 mm.", "The 12 mm standard width of HK1812FM is the general-purpose section at 18 mm shaft; wider HK variants in the same 18×24 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Needle rollers tolerate almost no misalignment; if the 24 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling." ], "faq": [ { "q": "What duty conditions suit a HK1812FM drawn-cup bearing?", "a": "HK1812FM is typically specified for dirty environments where the open ends rely entirely on the housing seals; match the grease/oil speed limits (8500/13000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK1812FM needle roller bearing?", "a": "A HK1812FM drawn-cup needle roller bearing has a 18 mm shaft diameter (Fw, under-roller diameter), 24 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1812FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1812FM, Fw = 18 mm, so the shaft must be machined to 18 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1812FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1812FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK1812FM need a hardened shaft?", "a": "Either the 18 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR15x18x12.5) so a standard unhardened shaft can be used." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK1816F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 18, "D_mm": 24, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 11.8, "static_load_kN": 17.3, "fatigue_load_limit_kN": 2.11, "limiting_speed_rpm": 8500, "speed_oil_rpm": 13000, "weight_g": 18, "manufacturer_designation": "HK1816F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK1816F", "HK1816F+IR15x18x16.5" ], "naming_rule_text": "HK1816F is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 18 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 24 mm and the width is 16 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. This size is specified in printing-press folder and cutter mechanisms, where the shaft is short, the loads are cyclical, and the thin cup lets the frame plates stay close together. When replacing this size, measure the housing bore with a plug gauge before pressing the new cup: a bore worn oversize by the previous bearing will not retain the new shell.", "applications": [ "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "compressor crankshaft supports", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "The HK1816F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Mid-size cups like HK1816F (18 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK1816F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 18 mm.", "The 16 mm standard width of HK1816F is the general-purpose section at 18 mm shaft; wider HK variants in the same 18×24 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK1816F need a hardened shaft?", "a": "Either the 18 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR15x18x16.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK1816F needle roller bearing?", "a": "A HK1816F drawn-cup needle roller bearing has a 18 mm shaft diameter (Fw, under-roller diameter), 24 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK1816F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK1816F, Fw = 18 mm, so the shaft must be machined to 18 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK1816F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK1816F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2012FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 20, "D_mm": 26, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 8.75, "static_load_kN": 12.1, "fatigue_load_limit_kN": 1.48, "limiting_speed_rpm": 8000, "speed_oil_rpm": 12000, "weight_g": 14, "manufacturer_designation": "HK2012FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2012FM", "HK2012FM+IR15x20x13" ], "naming_rule_text": "In the HK-series (ISO 3245), HK2012FM is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 20 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 26 mm cup outside diameter and 12 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. In this mid size range the HK cup is the standard compact radial bearing choice across automotive and industrial gearboxes. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "reciprocating or oscillating motion where the rollers never complete a full revolution" ], "failure_modes": [ "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed" ], "pitfalls": [ "The cage in HK2012FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 20 mm.", "The 12 mm standard width of HK2012FM is the general-purpose section at 20 mm shaft; wider HK variants in the same 20×26 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "The open ends of HK2012FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "At a 20 mm shaft diameter, check housing bore roundness after previous bearing removal for HK2012FM; a pulled or scored seat must be re-machined or sleeved before the new cup goes in." ], "faq": [ { "q": "What does Fw mean on a HK2012FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2012FM, Fw = 20 mm, so the shaft must be machined to 20 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2012FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2012FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2012FM need a hardened shaft?", "a": "Either the 20 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR15x20x13) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2012FM needle roller bearing?", "a": "A HK2012FM drawn-cup needle roller bearing has a 20 mm shaft diameter (Fw, under-roller diameter), 26 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2016F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 20, "D_mm": 26, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 12.5, "static_load_kN": 19.2, "fatigue_load_limit_kN": 2.34, "limiting_speed_rpm": 8000, "speed_oil_rpm": 12000, "weight_g": 19, "manufacturer_designation": "HK2016F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2016F", "HK2016F+IR17x20x16.5" ], "naming_rule_text": "In the HK-series (ISO 3245), HK2016F is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 20 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 26 mm cup outside diameter and 16 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Automotive gearbox designers default to this class when the radial envelope is fixed: the cup keeps the casing compact without giving up the required rating. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "compressor crankshaft supports", "agricultural machinery PTO drives", "universal joint and steering pivots", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Before pressing HK2016F in, verify the 20 mm housing seat is still round — extracting the old cup often pulls the bore, and the new thin shell will conform to any distortion.", "The cage in HK2016F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 20 mm.", "The 16 mm standard width of HK2016F is the general-purpose section at 20 mm shaft; wider HK variants in the same 20×26 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK2016F need a hardened shaft?", "a": "Either the 20 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR17x20x16.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2016F needle roller bearing?", "a": "A HK2016F drawn-cup needle roller bearing has a 20 mm shaft diameter (Fw, under-roller diameter), 26 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2016F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2016F, Fw = 20 mm, so the shaft must be machined to 20 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2016F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2016F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2020F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 20, "D_mm": 26, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 16, "static_load_kN": 26.2, "fatigue_load_limit_kN": 3.2, "limiting_speed_rpm": 8000, "speed_oil_rpm": 12000, "weight_g": 24, "manufacturer_designation": "HK2020F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2020F", "HK2020F+IR17x20x20.5" ], "naming_rule_text": "In the HK-series (ISO 3245), HK2020F is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 20 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 26 mm cup outside diameter and 20 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Marine outboard and small diesel linkage points use this size: the pressed-in cup tolerates the corrosion-prone environment better than a machined ring with a separate inner race. In high-speed applications, switch from grease to a circulating oil supply: the open ends let oil through, but grease at high speed channels and overheats the roller set.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "Drawn-cup needle bearings carry radial load only: HK2020F provides no axial shaft location — use separate thrust washers or a locating bearing for axial forces.", "The HK2020F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Mid-size cups like HK2020F (20 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK2020F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 20 mm.", "The 20 mm wide section of HK2020F gains rating through longer rollers at 20 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 20×26 mm narrow variant." ], "faq": [ { "q": "Does HK2020F need a hardened shaft?", "a": "Either the 20 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR17x20x20.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK2020F drawn-cup bearing?", "a": "HK2020F is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (8000/12000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK2020F needle roller bearing?", "a": "A HK2020F drawn-cup needle roller bearing has a 20 mm shaft diameter (Fw, under-roller diameter), 26 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2020F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2020F, Fw = 20 mm, so the shaft must be machined to 20 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2020F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2020F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2030ZWFD", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 20, "D_mm": 26, "B_mm": 30, "seal_type": "open", "dynamic_load_kN": 21.5, "static_load_kN": 38.5, "fatigue_load_limit_kN": 4.7, "limiting_speed_rpm": 8000, "speed_oil_rpm": 12000, "weight_g": 35, "manufacturer_designation": "HK2030ZWFD", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2030ZWFD", "HK2030ZWFD+IR17x20x30.5" ], "naming_rule_text": "In the HK-series (ISO 3245), HK2030ZWFD is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 20 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 26 mm cup outside diameter and 30 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The ZW suffix marks two roller rows in the same cup, roughly doubling the dynamic rating of the width-equivalent single-row version at the cost of the extra width. Automotive gearbox designers default to this class when the radial envelope is fixed: the cup keeps the casing compact without giving up the required rating. Marine outboard and small diesel linkage points use this size: the pressed-in cup tolerates the corrosion-prone environment better than a machined ring with a separate inner race. In high-speed applications, switch from grease to a circulating oil supply: the open ends let oil through, but grease at high speed channels and overheats the roller set.", "applications": [ "agricultural machinery PTO drives", "universal joint and steering pivots", "automotive manual transmission gear sets", "compact linkages where the cup doubles as both bearing and structural spacer" ], "failure_modes": [ "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection" ], "pitfalls": [ "The open ends of HK2030ZWFD retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "Before pressing HK2030ZWFD in, verify the 20 mm housing seat is still round — extracting the old cup often pulls the bore, and the new thin shell will conform to any distortion.", "The two roller rows in HK2030ZWFD share one cup: any shaft bending or housing-bore taper loads one row ahead of the other, so hold the 26 mm seat straight over the full 30 mm width and keep shaft deflection minimal.", "The 30 mm extra-wide section of HK2030ZWFD (double-row or extended roller set) is the high-capacity option at 20 mm shaft; the wider cup is more sensitive to housing bore alignment, so check bore straightness over the full 30 mm width.", "HK2030ZWFD runs directly on the shaft: the 20 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead." ], "faq": [ { "q": "What duty conditions suit a HK2030ZWFD drawn-cup bearing?", "a": "HK2030ZWFD is typically specified for lightly loaded high-speed idler positions where roller skidding must be watched; match the grease/oil speed limits (8000/12000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK2030ZWFD needle roller bearing?", "a": "A HK2030ZWFD drawn-cup needle roller bearing has a 20 mm shaft diameter (Fw, under-roller diameter), 26 mm outside diameter and 30 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2030ZWFD drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2030ZWFD, Fw = 20 mm, so the shaft must be machined to 20 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2030ZWFD needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2030ZWFD carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2030ZWFD need a hardened shaft?", "a": "Either the 20 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR17x20x30.5) so a standard unhardened shaft can be used." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2212FM", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 22, "D_mm": 28, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 9.2, "static_load_kN": 13.4, "fatigue_load_limit_kN": 1.63, "limiting_speed_rpm": 7500, "speed_oil_rpm": 11000, "weight_g": 13, "manufacturer_designation": "HK2212FM", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2212FM", "HK2212FM+IR17x22x13" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK2212FM is built around a thin hardened steel cup.Its printed envelope — 22 mm under-roller diameter, 28 mm outside diameter, 12 mm width — is fixed by ISO 3245; the 22 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The FM/FT2 suffix marks NTN's caged drawn-cup execution: a formed steel cage keeps the rollers evenly spaced, lowering friction and noise versus full-complement drawn cups. In this mid size range the HK cup is the standard compact radial bearing choice across automotive and industrial gearboxes. Compact hydraulic gear pumps use this size on their drive shafts: the pump housing is machined once, the cup is pressed home, and the shaft runs directly on the rollers for the life of the unit. For oscillating service, pack this size with a high-tackiness grease and re-lubricate at short intervals: the rollers do not complete a full revolution, so the same contact patch carries the load cycle after cycle.", "applications": [ "hydraulic pump and motor shafts", "compressor crankshaft supports", "agricultural machinery PTO drives", "compact linkages where the cup doubles as both bearing and structural spacer" ], "failure_modes": [ "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection" ], "pitfalls": [ "The open ends of HK2212FM retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "At a 22 mm shaft diameter, check housing bore roundness after previous bearing removal for HK2212FM; a pulled or scored seat must be re-machined or sleeved before the new cup goes in.", "The cage in HK2212FM spaces the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 22 mm.", "The 12 mm standard width of HK2212FM is the general-purpose section at 22 mm shaft; wider HK variants in the same 22×28 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "HK2212FM runs directly on the shaft: the 22 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead." ], "faq": [ { "q": "What duty conditions suit a HK2212FM drawn-cup bearing?", "a": "HK2212FM is typically specified for lightly loaded high-speed idler positions where roller skidding must be watched; match the grease/oil speed limits (7500/11000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK2212FM needle roller bearing?", "a": "A HK2212FM drawn-cup needle roller bearing has a 22 mm shaft diameter (Fw, under-roller diameter), 28 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2212FM drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2212FM, Fw = 22 mm, so the shaft must be machined to 22 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2212FM needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2212FM carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2212FM need a hardened shaft?", "a": "Either the 22 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR17x22x13) so a standard unhardened shaft can be used." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2216F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 22, "D_mm": 28, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 13.2, "static_load_kN": 21.1, "fatigue_load_limit_kN": 2.57, "limiting_speed_rpm": 7500, "speed_oil_rpm": 11000, "weight_g": 21, "manufacturer_designation": "HK2216F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2216F", "HK2216F+IR17x22x18" ], "naming_rule_text": "HK2216F is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 22 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 28 mm and the width is 16 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. This size is specified in printing-press folder and cutter mechanisms, where the shaft is short, the loads are cyclical, and the thin cup lets the frame plates stay close together. When replacing this size, measure the housing bore with a plug gauge before pressing the new cup: a bore worn oversize by the previous bearing will not retain the new shell.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "The open ends of HK2216F retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "Mid-size cups like HK2216F (22 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK2216F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 22 mm.", "The 16 mm standard width of HK2216F is the general-purpose section at 22 mm shaft; wider HK variants in the same 22×28 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK2216F need a hardened shaft?", "a": "Either the 22 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR17x22x18) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2216F needle roller bearing?", "a": "A HK2216F drawn-cup needle roller bearing has a 22 mm shaft diameter (Fw, under-roller diameter), 28 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2216F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2216F, Fw = 22 mm, so the shaft must be machined to 22 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2216F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2216F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2220F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 22, "D_mm": 28, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 16.8, "static_load_kN": 28.8, "fatigue_load_limit_kN": 3.5, "limiting_speed_rpm": 7500, "speed_oil_rpm": 11000, "weight_g": 26, "manufacturer_designation": "HK2220F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2220F", "HK2220F+IR17x22x20.5" ], "naming_rule_text": "HK2220F is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 22 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 28 mm and the width is 20 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Automotive gearbox designers default to this class when the radial envelope is fixed: the cup keeps the casing compact without giving up the required rating. Small compressor crankshafts and refrigeration equipment fit this size on the eccentric pin, where the housing bore is finish-bored in the same setup as the main bearing seats. Where the housing is a welded fabrication, finish-bore the seat after all welding and stress-relief is complete — pressing the cup into a distorted, as-welded bore guarantees early spalling.", "applications": [ "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "compressor crankshaft supports", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "The 20 mm wide section of HK2220F gains rating through longer rollers at 22 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 22×28 mm narrow variant.", "Needle rollers tolerate almost no misalignment; if the 28 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Before pressing HK2220F in, verify the 22 mm housing seat is still round — extracting the old cup often pulls the bore, and the new thin shell will conform to any distortion.", "The cage in HK2220F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 22 mm." ], "faq": [ { "q": "Can a HK2220F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2220F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2220F need a hardened shaft?", "a": "Either the 22 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR17x22x20.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK2220F drawn-cup bearing?", "a": "HK2220F is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (7500/11000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK2220F needle roller bearing?", "a": "A HK2220F drawn-cup needle roller bearing has a 22 mm shaft diameter (Fw, under-roller diameter), 28 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2220F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2220F, Fw = 22 mm, so the shaft must be machined to 22 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2512F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 25, "D_mm": 32, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 11.1, "static_load_kN": 15.2, "fatigue_load_limit_kN": 1.85, "limiting_speed_rpm": 6500, "speed_oil_rpm": 9500, "weight_g": 21, "manufacturer_designation": "HK2512F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2512F", "HK2512F+IR20x25x12.5" ], "naming_rule_text": "NTN HK2512F belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 25 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 32 mm outside and 12 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Agricultural PTO shafts and small tractor linkages use this size at the pivot points: the cup is pressed into a welded eye and forgotten until the implement is overhauled. Mounting this size in a split housing needs the cup pressed into one half only, with the joint face relieved so the shell is not pinched when the case bolts come up to torque.", "applications": [ "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "compressor crankshaft supports", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "The HK2512F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Mid-size cups like HK2512F (25 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "The cage in HK2512F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 25 mm.", "The 12 mm standard width of HK2512F is the general-purpose section at 25 mm shaft; wider HK variants in the same 25×32 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK2512F need a hardened shaft?", "a": "Either the 25 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR20x25x12.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2512F needle roller bearing?", "a": "A HK2512F drawn-cup needle roller bearing has a 25 mm shaft diameter (Fw, under-roller diameter), 32 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2512F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2512F, Fw = 25 mm, so the shaft must be machined to 25 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2512F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2512F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2516F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 25, "D_mm": 32, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 15.9, "static_load_kN": 24, "fatigue_load_limit_kN": 2.92, "limiting_speed_rpm": 6500, "speed_oil_rpm": 9500, "weight_g": 27, "manufacturer_designation": "HK2516F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2516F", "HK2516F+IR20x25x17" ], "naming_rule_text": "In the HK-series (ISO 3245), HK2516F is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 25 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 32 mm cup outside diameter and 16 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Automotive gearbox designers default to this class when the radial envelope is fixed: the cup keeps the casing compact without giving up the required rating. Conveyor and packaging-machinery builders choose this size for idler and tensioner rollers: the open ends accept a grease fill at assembly and the cup survives the life of the roller shell. When the housing is aluminium or magnesium, press this cup into a steel insert rather than the bare casting — differential thermal expansion will walk the cup out of a soft bore at operating temperature.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "intermittent duty with long standstill periods that invite false brinelling" ], "failure_modes": [ "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness" ], "pitfalls": [ "The open ends of HK2516F retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "Before pressing HK2516F in, verify the 25 mm housing seat is still round — extracting the old cup often pulls the bore, and the new thin shell will conform to any distortion.", "The cage in HK2516F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 25 mm.", "The 16 mm standard width of HK2516F is the general-purpose section at 25 mm shaft; wider HK variants in the same 25×32 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK2516F need a hardened shaft?", "a": "Either the 25 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR20x25x17) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2516F needle roller bearing?", "a": "A HK2516F drawn-cup needle roller bearing has a 25 mm shaft diameter (Fw, under-roller diameter), 32 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2516F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2516F, Fw = 25 mm, so the shaft must be machined to 25 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2516F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2516F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2520", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 25, "D_mm": 32, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 20.3, "static_load_kN": 33, "fatigue_load_limit_kN": 4, "limiting_speed_rpm": 6500, "speed_oil_rpm": 9500, "weight_g": 34, "manufacturer_designation": "HK2520", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2520", "HK2520+IR20x25x20.5" ], "naming_rule_text": "In the HK-series (ISO 3245), HK2520 is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 25 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 32 mm cup outside diameter and 20 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Conveyor and packaging-machinery builders choose this size for idler and tensioner rollers: the open ends accept a grease fill at assembly and the cup survives the life of the roller shell. When the housing is aluminium or magnesium, press this cup into a steel insert rather than the bare casting — differential thermal expansion will walk the cup out of a soft bore at operating temperature.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "Drawn-cup needle bearings carry radial load only: HK2520 provides no axial shaft location — use separate thrust washers or a locating bearing for axial forces.", "The HK2520 drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Mid-size cups like HK2520 (25 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "With no suffix letters, HK2520 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 25×32×20 mm match exactly — suffix conventions for cage and shell variants differ between makers.", "The 20 mm wide section of HK2520 gains rating through longer rollers at 25 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 25×32 mm narrow variant." ], "faq": [ { "q": "Does HK2520 need a hardened shaft?", "a": "Either the 25 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR20x25x20.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK2520 drawn-cup bearing?", "a": "HK2520 is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (6500/9500 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK2520 needle roller bearing?", "a": "A HK2520 drawn-cup needle roller bearing has a 25 mm shaft diameter (Fw, under-roller diameter), 32 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2520 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2520, Fw = 25 mm, so the shaft must be machined to 25 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2520 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2520 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2526C", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 25, "D_mm": 32, "B_mm": 26, "seal_type": "open", "dynamic_load_kN": 26.4, "static_load_kN": 46, "fatigue_load_limit_kN": 5.6, "limiting_speed_rpm": 6500, "speed_oil_rpm": 9500, "weight_g": 45, "manufacturer_designation": "HK2526C", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2526C", "HK2526C+IR20x25x26.5" ], "naming_rule_text": "The NTN HK2526C — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 25 mm is Fw, the under-roller (shaft journal) diameter; 32 mm and 26 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. Small electric actuators and valve gear specify this size on the output shaft, where the gearmotor pinion needs support but the casting leaves no room for a machined ring. In dusty environments, place an external lip seal or felt washer immediately adjacent to the open cup end; the rollers have no defence against grit that migrates through the housing.", "applications": [ "universal joint and steering pivots", "automotive manual transmission gear sets", "industrial gearbox lay shafts", "reciprocating or oscillating motion where the rollers never complete a full revolution" ], "failure_modes": [ "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Mid-size cups like HK2526C (25 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short.", "HK2526C carries a maker-specific variant code after the size: when substituting another brand, match the printed 25×32×26 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers.", "The 26 mm extra-wide section of HK2526C (double-row or extended roller set) is the high-capacity option at 25 mm shaft; the wider cup is more sensitive to housing bore alignment, so check bore straightness over the full 26 mm width." ], "faq": [ { "q": "Does HK2526C need a hardened shaft?", "a": "Either the 25 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR20x25x26.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2526C needle roller bearing?", "a": "A HK2526C drawn-cup needle roller bearing has a 25 mm shaft diameter (Fw, under-roller diameter), 32 mm outside diameter and 26 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2526C drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2526C, Fw = 25 mm, so the shaft must be machined to 25 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2526C needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2526C carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2538ZWD", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 25, "D_mm": 32, "B_mm": 38, "seal_type": "open", "dynamic_load_kN": 35, "static_load_kN": 65.5, "fatigue_load_limit_kN": 8, "limiting_speed_rpm": 6500, "speed_oil_rpm": 9500, "weight_g": 65, "manufacturer_designation": "HK2538ZWD", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2538ZWD", "HK2538ZWD+IR20x25x38.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK2538ZWD is built around a thin hardened steel cup.Its printed envelope — 25 mm under-roller diameter, 32 mm outside diameter, 38 mm width — is fixed by ISO 3245; the 25 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The ZW suffix marks two roller rows in the same cup, roughly doubling the dynamic rating of the width-equivalent single-row version at the cost of the extra width. Mid-size drawn cups like this appear throughout passenger-car and light-truck transmissions, pressed into cast housings where a machined ring would not fit. This size is specified in printing-press folder and cutter mechanisms, where the shaft is short, the loads are cyclical, and the thin cup lets the frame plates stay close together. When replacing this size, measure the housing bore with a plug gauge before pressing the new cup: a bore worn oversize by the previous bearing will not retain the new shell.", "applications": [ "automotive manual transmission gear sets", "industrial gearbox lay shafts", "hydraulic pump and motor shafts", "shock-loaded start-stop service such as clutch and kick-starter mechanisms" ], "failure_modes": [ "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell" ], "pitfalls": [ "The two roller rows in HK2538ZWD share one cup: any shaft bending or housing-bore taper loads one row ahead of the other, so hold the 32 mm seat straight over the full 38 mm width and keep shaft deflection minimal.", "The 38 mm extra-wide section of HK2538ZWD (double-row or extended roller set) is the high-capacity option at 25 mm shaft; the wider cup is more sensitive to housing bore alignment, so check bore straightness over the full 38 mm width.", "Drawn-cup needle bearings carry radial load only: HK2538ZWD provides no axial shaft location — use separate thrust washers or a locating bearing for axial forces.", "The HK2538ZWD drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Mid-size cups like HK2538ZWD (25 mm shaft) inherit the shape of their seat: a scored or oval housing bore from the previous bearing will cut the new bearing's life short." ], "faq": [ { "q": "What does Fw mean on a HK2538ZWD drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2538ZWD, Fw = 25 mm, so the shaft must be machined to 25 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2538ZWD needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2538ZWD carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2538ZWD need a hardened shaft?", "a": "Either the 25 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR20x25x38.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK2538ZWD drawn-cup bearing?", "a": "HK2538ZWD is typically specified for dirty environments where the open ends rely entirely on the housing seals; match the grease/oil speed limits (6500/9500 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK2538ZWD needle roller bearing?", "a": "A HK2538ZWD drawn-cup needle roller bearing has a 25 mm shaft diameter (Fw, under-roller diameter), 32 mm outside diameter and 38 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2816CT", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 28, "D_mm": 35, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 16.7, "static_load_kN": 26.4, "fatigue_load_limit_kN": 3.2, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8500, "weight_g": 30, "manufacturer_designation": "HK2816CT", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2816CT", "HK2816CT+IR22x28x17" ], "naming_rule_text": "The NTN HK2816CT — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 28 mm is Fw, the under-roller (shaft journal) diameter; 35 mm and 16 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. Garden machinery and small outboard engines fit this size in the crankcase web: the thin cup keeps the crank web narrow while still carrying the combustion pulses through the connecting-rod small end. Use a mandrel with a lead chamfer that matches the cup bore when pressing this size home; a flat-faced drift can catch the roller cage and distort the shell before it is fully seated.", "applications": [ "heavy gearbox and final drive shafts", "construction equipment swing pivots", "printing press cylinder journals", "compact linkages where the cup doubles as both bearing and structural spacer" ], "failure_modes": [ "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection" ], "pitfalls": [ "The press-fit of HK2816CT at 28 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "HK2816CT carries a maker-specific variant code after the size: when substituting another brand, match the printed 28×35×16 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers.", "The 16 mm standard width of HK2816CT is the general-purpose section at 28 mm shaft; wider HK variants in the same 28×35 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Needle rollers tolerate almost no misalignment; if the 35 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell." ], "faq": [ { "q": "What are the dimensions of a HK2816CT needle roller bearing?", "a": "A HK2816CT drawn-cup needle roller bearing has a 28 mm shaft diameter (Fw, under-roller diameter), 35 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2816CT drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2816CT, Fw = 28 mm, so the shaft must be machined to 28 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK2816CT needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2816CT carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2816CT need a hardened shaft?", "a": "Either the 28 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR22x28x17) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK2816CT drawn-cup bearing?", "a": "HK2816CT is typically specified for lightly loaded high-speed idler positions where roller skidding must be watched; match the grease/oil speed limits (5500/8500 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK2820", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 28, "D_mm": 35, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 21.3, "static_load_kN": 36, "fatigue_load_limit_kN": 4.4, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8500, "weight_g": 38, "manufacturer_designation": "HK2820", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK2820", "HK2820+IR22x28x20.5" ], "naming_rule_text": "The NTN HK2820 — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 28 mm is Fw, the under-roller (shaft journal) diameter; 35 mm and 20 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. This cup size is common in power-tool intermediate shafts — drills, saws, grinders — where the gearbox casing is magnesium or aluminium and the cup is pressed into a steel insert. If the shaft sees axial float, allow for it in the housing width — the cup cannot guide the shaft axially, and a shaft that walks will eventually hammer the open end of the shell.", "applications": [ "printing press cylinder journals", "machine tool feed drive supports", "marine steering and linkage shafts", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "The 20 mm wide section of HK2820 gains rating through longer rollers at 28 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 28×35 mm narrow variant.", "The HK2820 drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Pressing HK2820 (28 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder.", "With no suffix letters, HK2820 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 28×35×20 mm match exactly — suffix conventions for cage and shell variants differ between makers." ], "faq": [ { "q": "Can a HK2820 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK2820 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK2820 need a hardened shaft?", "a": "Either the 28 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR22x28x20.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK2820 needle roller bearing?", "a": "A HK2820 drawn-cup needle roller bearing has a 28 mm shaft diameter (Fw, under-roller diameter), 35 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK2820 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK2820, Fw = 28 mm, so the shaft must be machined to 28 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3012CT", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 30, "D_mm": 37, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 12.3, "static_load_kN": 18.2, "fatigue_load_limit_kN": 2.22, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8000, "weight_g": 24, "manufacturer_designation": "HK3012CT", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3012CT", "HK3012CT+IR25x30x12.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK3012CT is built around a thin hardened steel cup.Its printed envelope — 30 mm under-roller diameter, 37 mm outside diameter, 12 mm width — is fixed by ISO 3245; the 30 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. Model and hobby drivetrains, from RC cars to small robotics, use this size because the thin cup lets designers shrink the gearbox around the gears rather than around the bearing. For low-temperature service, verify the grease is rated for the minimum ambient — a standard lithium grease in this cup will stiffen and starve the rollers on a cold start.", "applications": [ "construction equipment swing pivots", "printing press cylinder journals", "machine tool feed drive supports", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "The HK3012CT drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life.", "Pressing HK3012CT (30 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder.", "HK3012CT carries a maker-specific variant code after the size: when substituting another brand, match the printed 30×37×12 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers.", "The 12 mm standard width of HK3012CT is the general-purpose section at 30 mm shaft; wider HK variants in the same 30×37 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK3012CT need a hardened shaft?", "a": "Either the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR25x30x12.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK3012CT needle roller bearing?", "a": "A HK3012CT drawn-cup needle roller bearing has a 30 mm shaft diameter (Fw, under-roller diameter), 37 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK3012CT drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3012CT, Fw = 30 mm, so the shaft must be machined to 30 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK3012CT needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3012CT carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "7E-HK3016C", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 30, "D_mm": 37, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 18.1, "static_load_kN": 30, "fatigue_load_limit_kN": 3.65, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8000, "weight_g": 32, "manufacturer_designation": "7E-HK3016C", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "7E-HK3016C", "7E-HK3016C+IR25x30x17" ], "naming_rule_text": "In the HK-series (ISO 3245), 7E-HK3016C is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 30 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 37 mm cup outside diameter and 16 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. You will find this cup size inside small two-stroke crankcases, supporting the small-end of the connecting rod where the housing is split and the bearing is pressed in before the case halves close. If the shaft cannot be hardened, press the matching IR inner ring onto it first; the ring gives the rollers a hardened, ground raceway and lets you keep a soft shaft for assembly reasons.", "applications": [ "printing press cylinder journals", "machine tool feed drive supports", "marine steering and linkage shafts", "heavily loaded slow pivots where static rating, not dynamic life, governs the choice" ], "failure_modes": [ "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting", "grease starvation in the open-end arrangement with no relubrication path" ], "pitfalls": [ "The 16 mm standard width of 7E-HK3016C is the general-purpose section at 30 mm shaft; wider HK variants in the same 30×37 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "7E-HK3016C runs directly on the shaft: the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of 7E-HK3016C retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "The press-fit of 7E-HK3016C at 30 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "7E-HK3016C carries a maker-specific variant code after the size: when substituting another brand, match the printed 30×37×16 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers." ], "faq": [ { "q": "Can a 7E-HK3016C needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like 7E-HK3016C carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does 7E-HK3016C need a hardened shaft?", "a": "Either the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR25x30x17) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a 7E-HK3016C drawn-cup bearing?", "a": "7E-HK3016C is typically specified for reciprocating or oscillating motion where the rollers never complete a full revolution; match the grease/oil speed limits (5500/8000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a 7E-HK3016C needle roller bearing?", "a": "A 7E-HK3016C drawn-cup needle roller bearing has a 30 mm shaft diameter (Fw, under-roller diameter), 37 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a 7E-HK3016C drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For 7E-HK3016C, Fw = 30 mm, so the shaft must be machined to 30 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3020F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 30, "D_mm": 37, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 22.3, "static_load_kN": 39.5, "fatigue_load_limit_kN": 4.8, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8000, "weight_g": 40, "manufacturer_designation": "HK3020F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3020F", "HK3020F+IR25x30x20.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK3020F is built around a thin hardened steel cup.Its printed envelope — 30 mm under-roller diameter, 37 mm outside diameter, 20 mm width — is fixed by ISO 3245; the 30 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. Small electric actuators and valve gear specify this size on the output shaft, where the gearmotor pinion needs support but the casting leaves no room for a machined ring. In dusty environments, place an external lip seal or felt washer immediately adjacent to the open cup end; the rollers have no defence against grit that migrates through the housing.", "applications": [ "machine tool feed drive supports", "marine steering and linkage shafts", "rolling mill auxiliary drives", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "The press-fit of HK3020F at 30 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "The cage in HK3020F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 30 mm.", "The 20 mm wide section of HK3020F gains rating through longer rollers at 30 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 30×37 mm narrow variant.", "HK3020F runs directly on the shaft: the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK3020F retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty." ], "faq": [ { "q": "What are the dimensions of a HK3020F needle roller bearing?", "a": "A HK3020F drawn-cup needle roller bearing has a 30 mm shaft diameter (Fw, under-roller diameter), 37 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK3020F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3020F, Fw = 30 mm, so the shaft must be machined to 30 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK3020F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3020F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK3020F need a hardened shaft?", "a": "Either the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR25x30x20.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK3020F drawn-cup bearing?", "a": "HK3020F is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (5500/8000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3026F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 30, "D_mm": 37, "B_mm": 26, "seal_type": "open", "dynamic_load_kN": 28.5, "static_load_kN": 54, "fatigue_load_limit_kN": 6.55, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8000, "weight_g": 53, "manufacturer_designation": "HK3026F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3026F", "HK3026F+IR25x30x26.5" ], "naming_rule_text": "The NTN HK3026F — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 30 mm is Fw, the under-roller (shaft journal) diameter; 37 mm and 26 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. This size is specified in printing-press folder and cutter mechanisms, where the shaft is short, the loads are cyclical, and the thin cup lets the frame plates stay close together. When replacing this size, measure the housing bore with a plug gauge before pressing the new cup: a bore worn oversize by the previous bearing will not retain the new shell.", "applications": [ "marine steering and linkage shafts", "rolling mill auxiliary drives", "heavy gearbox and final drive shafts", "shock-loaded start-stop service such as clutch and kick-starter mechanisms" ], "failure_modes": [ "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell" ], "pitfalls": [ "The 26 mm extra-wide section of HK3026F (double-row or extended roller set) is the high-capacity option at 30 mm shaft; the wider cup is more sensitive to housing bore alignment, so check bore straightness over the full 26 mm width.", "HK3026F runs directly on the shaft: the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK3026F retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "The press-fit of HK3026F at 30 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "The cage in HK3026F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 30 mm." ], "faq": [ { "q": "Can a HK3026F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3026F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK3026F need a hardened shaft?", "a": "Either the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR25x30x26.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK3026F drawn-cup bearing?", "a": "HK3026F is typically specified for dirty environments where the open ends rely entirely on the housing seals; match the grease/oil speed limits (5500/8000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK3026F needle roller bearing?", "a": "A HK3026F drawn-cup needle roller bearing has a 30 mm shaft diameter (Fw, under-roller diameter), 37 mm outside diameter and 26 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK3026F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3026F, Fw = 30 mm, so the shaft must be machined to 30 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3038ZWD", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 30, "D_mm": 37, "B_mm": 38, "seal_type": "open", "dynamic_load_kN": 38.5, "static_load_kN": 78.5, "fatigue_load_limit_kN": 9.6, "limiting_speed_rpm": 5500, "speed_oil_rpm": 8000, "weight_g": 76, "manufacturer_designation": "HK3038ZWD", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3038ZWD", "HK3038ZWD+IR25x30x38.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK3038ZWD is built around a thin hardened steel cup.Its printed envelope — 30 mm under-roller diameter, 37 mm outside diameter, 38 mm width — is fixed by ISO 3245; the 30 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The ZW suffix marks two roller rows in the same cup, roughly doubling the dynamic rating of the width-equivalent single-row version at the cost of the extra width. At this shaft size the cup carries substantial radial load, but correct press-fit practice and housing rigidity become decisive for reaching the calculated life. This size is specified in printing-press folder and cutter mechanisms, where the shaft is short, the loads are cyclical, and the thin cup lets the frame plates stay close together. When replacing this size, measure the housing bore with a plug gauge before pressing the new cup: a bore worn oversize by the previous bearing will not retain the new shell.", "applications": [ "rolling mill auxiliary drives", "heavy gearbox and final drive shafts", "construction equipment swing pivots", "reciprocating or oscillating motion where the rollers never complete a full revolution" ], "failure_modes": [ "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "At a 30 mm shaft diameter the press-in force for HK3038ZWD is substantial; use a press with a guided mandrel and confirm the cup seats against the housing shoulder — a cocked cup concentrates load on the outermost roller row.", "The two roller rows in HK3038ZWD share one cup: any shaft bending or housing-bore taper loads one row ahead of the other, so hold the 37 mm seat straight over the full 38 mm width and keep shaft deflection minimal.", "The 38 mm extra-wide section of HK3038ZWD (double-row or extended roller set) is the high-capacity option at 30 mm shaft; the wider cup is more sensitive to housing bore alignment, so check bore straightness over the full 38 mm width." ], "faq": [ { "q": "Does HK3038ZWD need a hardened shaft?", "a": "Either the 30 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR25x30x38.5) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK3038ZWD needle roller bearing?", "a": "A HK3038ZWD drawn-cup needle roller bearing has a 30 mm shaft diameter (Fw, under-roller diameter), 37 mm outside diameter and 38 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK3038ZWD drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3038ZWD, Fw = 30 mm, so the shaft must be machined to 30 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK3038ZWD needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3038ZWD carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3512CV2", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 35, "D_mm": 42, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 13.3, "static_load_kN": 21.3, "fatigue_load_limit_kN": 2.6, "limiting_speed_rpm": 4700, "speed_oil_rpm": 7000, "weight_g": 28, "manufacturer_designation": "HK3512CV2", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3512CV2" ], "naming_rule_text": "The NTN HK3512CV2 — an open-end drawn-cup needle roller bearing — sits in the HK-series under ISO 3245 boundary dimensions.Reading the size code: 35 mm is Fw, the under-roller (shaft journal) diameter; 42 mm and 12 mm are the cup outside diameter and width respectively. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. Agricultural PTO shafts and small tractor linkages use this size at the pivot points: the cup is pressed into a welded eye and forgotten until the implement is overhauled. Mounting this size in a split housing needs the cup pressed into one half only, with the joint face relieved so the shell is not pinched when the case bolts come up to torque.", "applications": [ "heavy gearbox and final drive shafts", "construction equipment swing pivots", "printing press cylinder journals", "shock-loaded start-stop service such as clutch and kick-starter mechanisms" ], "failure_modes": [ "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell" ], "pitfalls": [ "Pressing HK3512CV2 (35 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder.", "HK3512CV2 carries a maker-specific variant code after the size: when substituting another brand, match the printed 35×42×12 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers.", "The 12 mm standard width of HK3512CV2 is the general-purpose section at 35 mm shaft; wider HK variants in the same 35×42 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Needle rollers tolerate almost no misalignment; if the 42 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell." ], "faq": [ { "q": "What are the dimensions of a HK3512CV2 needle roller bearing?", "a": "A HK3512CV2 drawn-cup needle roller bearing has a 35 mm shaft diameter (Fw, under-roller diameter), 42 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK3512CV2 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3512CV2, Fw = 35 mm, so the shaft must be machined to 35 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK3512CV2 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3512CV2 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK3512CV2 retained in the housing?", "a": "The thin-walled drawn cup of HK3512CV2 is press-fitted into a 42 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What duty conditions suit a HK3512CV2 drawn-cup bearing?", "a": "HK3512CV2 is typically specified for dirty environments where the open ends rely entirely on the housing seals; match the grease/oil speed limits (4700/7000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3516CT", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 35, "D_mm": 42, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 19, "static_load_kN": 33.5, "fatigue_load_limit_kN": 4.1, "limiting_speed_rpm": 4700, "speed_oil_rpm": 7000, "weight_g": 37, "manufacturer_designation": "HK3516CT", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3516CT" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK3516CT is built around a thin hardened steel cup.Its printed envelope — 35 mm under-roller diameter, 42 mm outside diameter, 16 mm width — is fixed by ISO 3245; the 35 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. Conveyor and packaging-machinery builders choose this size for idler and tensioner rollers: the open ends accept a grease fill at assembly and the cup survives the life of the roller shell. When the housing is aluminium or magnesium, press this cup into a steel insert rather than the bare casting — differential thermal expansion will walk the cup out of a soft bore at operating temperature.", "applications": [ "machine tool feed drive supports", "marine steering and linkage shafts", "rolling mill auxiliary drives", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "HK3516CT carries a maker-specific variant code after the size: when substituting another brand, match the printed 35×42×16 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers.", "The 16 mm standard width of HK3516CT is the general-purpose section at 35 mm shaft; wider HK variants in the same 35×42 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Pressing HK3516CT (35 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder." ], "faq": [ { "q": "What does Fw mean on a HK3516CT drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3516CT, Fw = 35 mm, so the shaft must be machined to 35 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK3516CT needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3516CT carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK3516CT retained in the housing?", "a": "The thin-walled drawn cup of HK3516CT is press-fitted into a 42 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What are the dimensions of a HK3516CT needle roller bearing?", "a": "A HK3516CT drawn-cup needle roller bearing has a 35 mm shaft diameter (Fw, under-roller diameter), 42 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK3520", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 35, "D_mm": 42, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 24.8, "static_load_kN": 47.5, "fatigue_load_limit_kN": 5.8, "limiting_speed_rpm": 4700, "speed_oil_rpm": 7000, "weight_g": 46, "manufacturer_designation": "HK3520", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK3520" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK3520 is built around a thin hardened steel cup.Its printed envelope — 35 mm under-roller diameter, 42 mm outside diameter, 20 mm width — is fixed by ISO 3245; the 35 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. Model and hobby drivetrains, from RC cars to small robotics, use this size because the thin cup lets designers shrink the gearbox around the gears rather than around the bearing. For low-temperature service, verify the grease is rated for the minimum ambient — a standard lithium grease in this cup will stiffen and starve the rollers on a cold start.", "applications": [ "machine tool feed drive supports", "marine steering and linkage shafts", "rolling mill auxiliary drives", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "Pressing HK3520 (35 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder.", "With no suffix letters, HK3520 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 35×42×20 mm match exactly — suffix conventions for cage and shell variants differ between makers.", "The 20 mm wide section of HK3520 gains rating through longer rollers at 35 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 35×42 mm narrow variant.", "HK3520 runs directly on the shaft: the 35 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK3520 retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty." ], "faq": [ { "q": "What are the dimensions of a HK3520 needle roller bearing?", "a": "A HK3520 drawn-cup needle roller bearing has a 35 mm shaft diameter (Fw, under-roller diameter), 42 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK3520 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK3520, Fw = 35 mm, so the shaft must be machined to 35 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK3520 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK3520 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "How is a HK3520 retained in the housing?", "a": "The thin-walled drawn cup of HK3520 is press-fitted into a 42 mm housing bore (typically N6/N7 tolerance for steel housings). The press fit alone retains the cup — no snap rings or shoulders are needed, but the bore must be round and rigid." }, { "q": "What duty conditions suit a HK3520 drawn-cup bearing?", "a": "HK3520 is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (4700/7000 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK4012V2", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 40, "D_mm": 47, "B_mm": 12, "seal_type": "open", "dynamic_load_kN": 12.1, "static_load_kN": 19.5, "fatigue_load_limit_kN": 2.38, "limiting_speed_rpm": 4000, "speed_oil_rpm": 6000, "weight_g": 31, "manufacturer_designation": "HK4012V2", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK4012V2", "HK4012V2+IR35x40x12.5" ], "naming_rule_text": "In the HK-series (ISO 3245), HK4012V2 is NTN's open-end drawn-cup needle roller bearing.Boundary dimensions are 40 mm under-roller diameter (Fw — the shaft journal acts as the raceway), 47 mm cup outside diameter and 12 mm width. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. Industrial sewing machines and textile equipment run this size on their shuttle and needle-bar drive shafts, where the compact radial section keeps the arm profile slim. Shaft tolerance for this size is h5 or j5: the roller complement needs a controlled radial clearance, and a shaft ground to general-purpose tolerances can leave the bearing either slack or pinched.", "applications": [ "printing press cylinder journals", "machine tool feed drive supports", "marine steering and linkage shafts", "compact linkages where the cup doubles as both bearing and structural spacer" ], "failure_modes": [ "grease starvation in the open-end arrangement with no relubrication path", "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection" ], "pitfalls": [ "The 12 mm standard width of HK4012V2 is the general-purpose section at 40 mm shaft; wider HK variants in the same 40×47 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "HK4012V2 runs directly on the shaft: the 40 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or fit the matching IR inner ring instead.", "The open ends of HK4012V2 retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "The press-fit of HK4012V2 at 40 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "HK4012V2 carries a maker-specific variant code after the size: when substituting another brand, match the printed 40×47×12 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers." ], "faq": [ { "q": "Can a HK4012V2 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK4012V2 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK4012V2 need a hardened shaft?", "a": "Either the 40 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR35x40x12.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK4012V2 drawn-cup bearing?", "a": "HK4012V2 is typically specified for lightly loaded high-speed idler positions where roller skidding must be watched; match the grease/oil speed limits (4000/6000 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK4012V2 needle roller bearing?", "a": "A HK4012V2 drawn-cup needle roller bearing has a 40 mm shaft diameter (Fw, under-roller diameter), 47 mm outside diameter and 12 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK4012V2 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK4012V2, Fw = 40 mm, so the shaft must be machined to 40 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK4016CT", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 40, "D_mm": 47, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 20.3, "static_load_kN": 38.5, "fatigue_load_limit_kN": 4.7, "limiting_speed_rpm": 4000, "speed_oil_rpm": 6000, "weight_g": 41, "manufacturer_designation": "HK4016CT", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK4016CT", "HK4016CT+IR35x40x17" ], "naming_rule_text": "HK4016CT is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 40 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 47 mm and the width is 16 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The trailing code letters mark a production-variant shell or cage execution; the boundary dimensions match the base HK size, so interchange checks should rely on the printed Fw/D/C values. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "machine tool feed drive supports", "marine steering and linkage shafts", "rolling mill auxiliary drives", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "The press-fit of HK4016CT at 40 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "HK4016CT carries a maker-specific variant code after the size: when substituting another brand, match the printed 40×47×16 mm boundary dimensions and load ratings rather than the suffix letters, which are not standardized across makers.", "The 16 mm standard width of HK4016CT is the general-purpose section at 40 mm shaft; wider HK variants in the same 40×47 mm envelope carry more load and are not interchangeable if the housing width is fixed." ], "faq": [ { "q": "Does HK4016CT need a hardened shaft?", "a": "Either the 40 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR35x40x17) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK4016CT needle roller bearing?", "a": "A HK4016CT drawn-cup needle roller bearing has a 40 mm shaft diameter (Fw, under-roller diameter), 47 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK4016CT drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK4016CT, Fw = 40 mm, so the shaft must be machined to 40 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK4016CT needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK4016CT carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK4020F", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 40, "D_mm": 47, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 25.9, "static_load_kN": 52.5, "fatigue_load_limit_kN": 6.4, "limiting_speed_rpm": 4000, "speed_oil_rpm": 6000, "weight_g": 52, "manufacturer_designation": "HK4020F", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK4020F", "HK4020F+IR35x40x20.5" ], "naming_rule_text": "As an open-end drawn-cup needle roller bearing in the HK-series (ISO 3245), NTN HK4020F is built around a thin hardened steel cup.Its printed envelope — 40 mm under-roller diameter, 47 mm outside diameter, 20 mm width — is fixed by ISO 3245; the 40 mm figure is the shaft journal itself, which carries the rollers directly. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. The F suffix marks NTN's caged drawn-cup execution: a formed steel cage spaces the rollers, lowering friction versus full-complement drawn cups. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. You will find this cup size inside small two-stroke crankcases, supporting the small-end of the connecting rod where the housing is split and the bearing is pressed in before the case halves close. If the shaft cannot be hardened, press the matching IR inner ring onto it first; the ring gives the rollers a hardened, ground raceway and lets you keep a soft shaft for assembly reasons.", "applications": [ "printing press cylinder journals", "machine tool feed drive supports", "marine steering and linkage shafts", "lightly loaded high-speed idler positions where roller skidding must be watched" ], "failure_modes": [ "cage wear or fracture from sustained operation near the limiting speed", "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat" ], "pitfalls": [ "The press-fit of HK4020F at 40 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "The cage in HK4020F guides the rollers but is not a seal: it retains nothing against dust or washdown, so the housing still needs its own sealing arrangement at 40 mm.", "The 20 mm wide section of HK4020F gains rating through longer rollers at 40 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 40×47 mm narrow variant.", "The HK4020F drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life." ], "faq": [ { "q": "What are the dimensions of a HK4020F needle roller bearing?", "a": "A HK4020F drawn-cup needle roller bearing has a 40 mm shaft diameter (Fw, under-roller diameter), 47 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK4020F drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK4020F, Fw = 40 mm, so the shaft must be machined to 40 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK4020F needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK4020F carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK4020F need a hardened shaft?", "a": "Either the 40 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR35x40x20.5) so a standard unhardened shaft can be used." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK4516", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 45, "D_mm": 52, "B_mm": 16, "seal_type": "open", "dynamic_load_kN": 21.6, "static_load_kN": 43, "fatigue_load_limit_kN": 5.25, "limiting_speed_rpm": 3700, "speed_oil_rpm": 5500, "weight_g": 46, "manufacturer_designation": "HK4516", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK4516", "HK4516+IR40x45x17" ], "naming_rule_text": "HK4516 is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 45 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 52 mm and the width is 16 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. Industrial sewing machines and textile equipment run this size on their shuttle and needle-bar drive shafts, where the compact radial section keeps the arm profile slim. Shaft tolerance for this size is h5 or j5: the roller complement needs a controlled radial clearance, and a shaft ground to general-purpose tolerances can leave the bearing either slack or pinched.", "applications": [ "rolling mill auxiliary drives", "heavy gearbox and final drive shafts", "construction equipment swing pivots", "reciprocating or oscillating motion where the rollers never complete a full revolution" ], "failure_modes": [ "raceway spalling on a shaft that was below the required 58–64 HRC hardness", "edge loading and needle skewing under shaft misalignment or deflection", "cage wear or fracture from sustained operation near the limiting speed" ], "pitfalls": [ "With no suffix letters, HK4516 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 45×52×16 mm match exactly — suffix conventions for cage and shell variants differ between makers.", "The 16 mm standard width of HK4516 is the general-purpose section at 45 mm shaft; wider HK variants in the same 45×52 mm envelope carry more load and are not interchangeable if the housing width is fixed.", "The open ends of HK4516 retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "The press-fit of HK4516 at 45 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row." ], "faq": [ { "q": "What does Fw mean on a HK4516 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK4516, Fw = 45 mm, so the shaft must be machined to 45 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK4516 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK4516 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK4516 need a hardened shaft?", "a": "Either the 45 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR40x45x17) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK4516 needle roller bearing?", "a": "A HK4516 drawn-cup needle roller bearing has a 45 mm shaft diameter (Fw, under-roller diameter), 52 mm outside diameter and 16 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK4520", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 45, "D_mm": 52, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 27.6, "static_load_kN": 59, "fatigue_load_limit_kN": 7.2, "limiting_speed_rpm": 3700, "speed_oil_rpm": 5500, "weight_g": 58, "manufacturer_designation": "HK4520", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK4520", "HK4520+IR40x45x20.5" ], "naming_rule_text": "HK4520 is an NTN drawn-cup needle roller bearing with open ends in the HK-series (ISO 3245 boundary dimensions).The designation encodes the shaft fit directly: Fw = 45 mm is the under-roller diameter, i.e. the shaft journal that serves as the inner raceway; the cup outside diameter is 52 mm and the width is 20 mm. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. In this class the limiting factor is rarely the rating table — a poorly supported or out-of-round seat will end the bearing long before fatigue does. This cup size is common in power-tool intermediate shafts — drills, saws, grinders — where the gearbox casing is magnesium or aluminium and the cup is pressed into a steel insert. If the shaft sees axial float, allow for it in the housing width — the cup cannot guide the shaft axially, and a shaft that walks will eventually hammer the open end of the shell.", "applications": [ "construction equipment swing pivots", "printing press cylinder journals", "machine tool feed drive supports", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "The 20 mm wide section of HK4520 gains rating through longer rollers at 45 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 45×52 mm narrow variant.", "Needle rollers tolerate almost no misalignment; if the 52 mm housing seat cannot be held square to the shaft, expect edge loading and early spalling.", "Press the drawn cup in with a mandrel bearing on the stamped face only — never hammer the cup or press through the rollers, that cracks or brinells the shell.", "Pressing HK4520 (45 mm shaft) home needs real force: keep the cup square with a guided mandrel, because a tilted cup overloads the roller row nearest the shoulder.", "With no suffix letters, HK4520 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 45×52×20 mm match exactly — suffix conventions for cage and shell variants differ between makers." ], "faq": [ { "q": "Can a HK4520 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK4520 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK4520 need a hardened shaft?", "a": "Either the 45 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR40x45x20.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK4520 drawn-cup bearing?", "a": "HK4520 is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (3700/5500 rpm) and radial load against the actual duty before finalizing." }, { "q": "What are the dimensions of a HK4520 needle roller bearing?", "a": "A HK4520 drawn-cup needle roller bearing has a 45 mm shaft diameter (Fw, under-roller diameter), 52 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK4520 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK4520, Fw = 45 mm, so the shaft must be machined to 45 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK5020", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 50, "D_mm": 58, "B_mm": 20, "seal_type": "open", "dynamic_load_kN": 31.5, "static_load_kN": 63, "fatigue_load_limit_kN": 7.7, "limiting_speed_rpm": 3200, "speed_oil_rpm": 4800, "weight_g": 72, "manufacturer_designation": "HK5020", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK5020", "HK5020+IR40x50x22" ], "naming_rule_text": "NTN HK5020 belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 50 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 58 mm outside and 20 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.", "applications": [ "heavy gearbox and final drive shafts", "construction equipment swing pivots", "printing press cylinder journals", "dirty environments where the open ends rely entirely on the housing seals" ], "failure_modes": [ "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends", "brinelling of the drawn cup from hammer blows during press-in mounting" ], "pitfalls": [ "The 20 mm wide section of HK5020 gains rating through longer rollers at 50 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 50×58 mm narrow variant.", "The open ends of HK5020 retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.", "The press-fit of HK5020 at 50 mm shaft size must be done in one smooth stroke: stopping mid-way or driving at an angle leaves the cup cocked and the load on one roller row.", "With no suffix letters, HK5020 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 50×58×20 mm match exactly — suffix conventions for cage and shell variants differ between makers." ], "faq": [ { "q": "Can a HK5020 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK5020 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK5020 need a hardened shaft?", "a": "Either the 50 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR40x50x22) so a standard unhardened shaft can be used." }, { "q": "What are the dimensions of a HK5020 needle roller bearing?", "a": "A HK5020 drawn-cup needle roller bearing has a 50 mm shaft diameter (Fw, under-roller diameter), 58 mm outside diameter and 20 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK5020 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK5020, Fw = 50 mm, so the shaft must be machined to 50 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" }, { "sku": "HK5025", "brand": "NTN", "series": "HK-series", "type": "needle", "d_mm": 50, "D_mm": 58, "B_mm": 25, "seal_type": "open", "dynamic_load_kN": 38.5, "static_load_kN": 82, "fatigue_load_limit_kN": 10, "limiting_speed_rpm": 3200, "speed_oil_rpm": 4800, "weight_g": 90, "manufacturer_designation": "HK5025", "standard": "ISO 3245", "source_ref": "https://www.ntnglobal.com/", "catalog_ver": "CAT. No. 2203-3/E 2024", "extracted_at": "2026-09-25", "aliases": [ "HK5025", "HK5025+IR45x50x25.5" ], "naming_rule_text": "NTN HK5025 belongs to the HK-series of open-end drawn-cup needle roller bearings (ISO 3245).Fw = 50 mm names the shaft journal that doubles as the inner raceway; around it the drawn cup measures 58 mm outside and 25 mm across. There is no separate inner ring — the thin-walled cup is drawn from sheet steel, hardened, and press-fitted into the housing, giving the smallest radial section of any rolling bearing at this shaft size. No suffix letters follow the size code: this is the basic caged drawn-cup execution in the HK range. At this shaft size the cup carries substantial radial load, but correct press-fit practice and housing rigidity become decisive for reaching the calculated life. You will find this cup size inside small two-stroke crankcases, supporting the small-end of the connecting rod where the housing is split and the bearing is pressed in before the case halves close. If the shaft cannot be hardened, press the matching IR inner ring onto it first; the ring gives the rollers a hardened, ground raceway and lets you keep a soft shaft for assembly reasons.", "applications": [ "heavy gearbox and final drive shafts", "construction equipment swing pivots", "printing press cylinder journals", "continuous high-speed rotation where grease redistribution is the limiting factor" ], "failure_modes": [ "cup cracking from an oval or tapered housing bore distorting the thin shell", "fretting of the cup outer surface in a soft or worn housing seat", "scoring of the needle rollers from abrasive contamination past the open ends" ], "pitfalls": [ "At a 50 mm shaft diameter the press-in force for HK5025 is substantial; use a press with a guided mandrel and confirm the cup seats against the housing shoulder — a cocked cup concentrates load on the outermost roller row.", "With no suffix letters, HK5025 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 50×58×25 mm match exactly — suffix conventions for cage and shell variants differ between makers.", "The 25 mm extra-wide section of HK5025 (double-row or extended roller set) is the high-capacity option at 50 mm shaft; the wider cup is more sensitive to housing bore alignment, so check bore straightness over the full 25 mm width.", "Drawn-cup needle bearings carry radial load only: HK5025 provides no axial shaft location — use separate thrust washers or a locating bearing for axial forces.", "The HK5025 drawn cup is a thin shell that takes the shape of its housing: the housing bore must be machined to tolerance (typically N6/N7 for steel housings) — a worn or oval seat distorts the cup and cuts life." ], "faq": [ { "q": "What are the dimensions of a HK5025 needle roller bearing?", "a": "A HK5025 drawn-cup needle roller bearing has a 50 mm shaft diameter (Fw, under-roller diameter), 58 mm outside diameter and 25 mm width, per ISO 3245 boundary dimensions. It has no inner ring — the shaft journal serves as the raceway." }, { "q": "What does Fw mean on a HK5025 drawn-cup bearing?", "a": "Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK5025, Fw = 50 mm, so the shaft must be machined to 50 mm, hardened to 58–64 HRC and ground, unless a separate IR inner ring is fitted." }, { "q": "Can a HK5025 needle roller bearing carry axial load?", "a": "No. Drawn-cup needle roller bearings like HK5025 carry radial load only and provide no axial shaft location. Axial forces must be carried by separate thrust washers or a locating bearing in the arrangement." }, { "q": "Does HK5025 need a hardened shaft?", "a": "Either the 50 mm shaft journal must be hardened to 58–64 HRC and ground to Ra ≤ 0.2 µm, or you can fit the matching inner ring (IR45x50x25.5) so a standard unhardened shaft can be used." }, { "q": "What duty conditions suit a HK5025 drawn-cup bearing?", "a": "HK5025 is typically specified for intermittent duty with long standstill periods that invite false brinelling; match the grease/oil speed limits (3200/4800 rpm) and radial load against the actual duty before finalizing." } ], "confidence_score": 0.7, "status": "published", "last_verified": "2026-09-25" } ]