HK1412FM bearing: complete specifications & equivalents
The HK1412FM is a ISO 3245 radial bearing sized 14 x 20 x 12 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 14 mm |
| Outer diameter D | 20 mm |
| Width B | 12 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 7.2 kN |
| Basic static load rating C0 | 8.5 kN |
| Fatigue load limit Pu | 1.04 kN |
| Limiting speed (mechanical) | 11000 rpm |
| Mass | 11 g |
| Manufacturer designation | HK1412FM |
| Standard | ISO 3245 |
| Catalog version | CAT. No. 2203-3/E 2024 |
| Last verified | 2026-09-25 |
Source: catalog reference (CAT. No. 2203-3/E 2024) · extracted 2026-09-25
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (CAT. No. 2203-3/E 2024); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & HK-series range
| Bore d | 0.551 in |
|---|---|
| Outer diameter D | 0.787 in |
| Width B | 0.472 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 3 mm |
| Smallest bore in HK-series | 3 mm |
| Largest outer diameter in HK-series | 58 mm |
| Width range across HK-series | 6–38 mm |
| Bore position in HK-series (smallest first) | 11 of 24 |
| Bore above smallest HK-series size | 11 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the HK1412FM model number is decoded
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.
Typical equipment & failure modes
Common 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
Known failure patterns
- 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
Selection pitfalls — read before you substitute
- 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.
Frequently asked questions
What are the dimensions of a HK1412FM needle roller bearing?
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.
What does Fw mean on a HK1412FM drawn-cup bearing?
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.
Can a HK1412FM needle roller bearing carry axial load?
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.
Does HK1412FM need a hardened shaft?
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.
What duty conditions suit a HK1412FM drawn-cup bearing?
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.
Reviewed & verified by the MPN Base engineering desk against source catalog CAT. No. 2203-3/E 2024 on 2026-09-25. Read our editorial & correction policy.