HK5025 bearing: complete specifications & equivalents
The HK5025 is a ISO 3245 radial bearing sized 50 x 58 x 25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 50 mm |
| Outer diameter D | 58 mm |
| Width B | 25 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 38.5 kN |
| Basic static load rating C0 | 82 kN |
| Fatigue load limit Pu | 10 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Mass | 90 g |
| Manufacturer designation | HK5025 |
| 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 | 1.969 in |
|---|---|
| Outer diameter D | 2.283 in |
| Width B | 0.984 in |
| ISO bore code | 25 |
| Radial section height (D−d)/2 | 4 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) | 24 of 24 |
| Bore above smallest HK-series size | 47 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the HK5025 model number is decoded
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.
Typical equipment & failure modes
Common 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
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
- 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.
Frequently asked questions
What are the dimensions of a HK5025 needle roller bearing?
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.
What does Fw mean on a HK5025 drawn-cup bearing?
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.
Can a HK5025 needle roller bearing carry axial load?
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.
Does HK5025 need a hardened shaft?
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.
What duty conditions suit a HK5025 drawn-cup bearing?
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.
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.