HK2520 bearing: complete specifications & equivalents
The HK2520 is a ISO 3245 radial bearing sized 25 x 32 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 | 25 mm |
| Outer diameter D | 32 mm |
| Width B | 20 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 20.3 kN |
| Basic static load rating C0 | 33 kN |
| Fatigue load limit Pu | 4 kN |
| Limiting speed (mechanical) | 6500 rpm |
| Mass | 34 g |
| Manufacturer designation | HK2520 |
| 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 | 0.984 in |
|---|---|
| Outer diameter D | 1.26 in |
| Width B | 0.787 in |
| ISO bore code | 20 |
| 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) | 18 of 24 |
| Bore above smallest HK-series size | 22 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the HK2520 model number is decoded
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.
Typical equipment & failure modes
Common 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
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
- 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.
Frequently asked questions
Does HK2520 need a hardened shaft?
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.
What duty conditions suit a HK2520 drawn-cup bearing?
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.
What are the dimensions of a HK2520 needle roller bearing?
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.
What does Fw mean on a HK2520 drawn-cup bearing?
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.
Can a HK2520 needle roller bearing carry axial load?
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.
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.