HK1612FM bearing: complete specifications & equivalents
The HK1612FM is a ISO 3245 radial bearing sized 16 x 22 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 | 16 mm |
| Outer diameter D | 22 mm |
| Width B | 12 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 7.75 kN |
| Basic static load rating C0 | 9.7 kN |
| Fatigue load limit Pu | 1.18 kN |
| Limiting speed (mechanical) | 10000 rpm |
| Mass | 12 g |
| Manufacturer designation | HK1612FM |
| 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 | 0.63 in |
|---|---|
| Outer diameter D | 0.866 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) | 13 of 24 |
| Bore above smallest HK-series size | 13 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the HK1612FM model number is decoded
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.
Typical equipment & failure modes
Common 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
Known failure patterns
- 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
Selection pitfalls — read before you substitute
- 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.
Frequently asked questions
Does HK1612FM need a hardened shaft?
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.
What are the dimensions of a HK1612FM needle roller bearing?
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.
What does Fw mean on a HK1612FM drawn-cup bearing?
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.
Can a HK1612FM needle roller bearing carry axial load?
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.
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.