HK3020F bearing: complete specifications & equivalents
The HK3020F is a ISO 3245 radial bearing sized 30 x 37 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 30 mm |
| Outer diameter D | 37 mm |
| Width B | 20 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 22.3 kN |
| Basic static load rating C0 | 39.5 kN |
| Fatigue load limit Pu | 4.8 kN |
| Limiting speed (mechanical) | 5500 rpm |
| Mass | 40 g |
| Manufacturer designation | HK3020F |
| 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 | 1.181 in |
|---|---|
| Outer diameter D | 1.457 in |
| Width B | 0.787 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 3.5 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) | 20 of 24 |
| Bore above smallest HK-series size | 27 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the HK3020F model number is decoded
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.
Typical equipment & failure modes
Common 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
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
- 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.
Frequently asked questions
What are the dimensions of a HK3020F needle roller bearing?
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.
What does Fw mean on a HK3020F drawn-cup bearing?
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.
Can a HK3020F needle roller bearing carry axial load?
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.
Does HK3020F need a hardened shaft?
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.
What duty conditions suit a HK3020F drawn-cup bearing?
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.
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.