HK5020 bearing: complete specifications & equivalents
The HK5020 is a ISO 3245 radial bearing sized 50 x 58 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 | 50 mm |
| Outer diameter D | 58 mm |
| Width B | 20 mm |
| Seal / shield | open |
| Basic dynamic load rating C | 31.5 kN |
| Basic static load rating C0 | 63 kN |
| Fatigue load limit Pu | 7.7 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Mass | 72 g |
| Manufacturer designation | HK5020 |
| 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 | 0.787 in |
| ISO bore code | 20 |
| 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 HK5020 model number is decoded
NTN HK5020 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 20 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. Larger drawn cups demand more of the housing: cast seats should be checked for roundness and rigidity before the cup is pressed in. This size is frequently specified in motorcycle gear-selector mechanisms, where the shaft is short, the housing is cast around the bearing, and the roller set must survive repeated shock from shift forks. Grease for this size should be a soft NLGI 1 or 2 lithium-complex grade: the open cup lets the housing supply the lubricant, and a stiff grease will not flow back through the roller set after standstill.
Typical equipment & failure modes
Common applications
- heavy gearbox and final drive shafts
- construction equipment swing pivots
- printing press cylinder journals
- dirty environments where the open ends rely entirely on the housing seals
Known failure patterns
- 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
- brinelling of the drawn cup from hammer blows during press-in mounting
Selection pitfalls — read before you substitute
- The 20 mm wide section of HK5020 gains rating through longer rollers at 50 mm shaft; confirm the housing width accepts 20 mm — it will not drop into a seat machined for the 50×58 mm narrow variant.
- The open ends of HK5020 retain no lubricant: grease must be supplied by the housing arrangement, and adjacent seals are needed in dirty or washdown duty.
- The press-fit of HK5020 at 50 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.
- With no suffix letters, HK5020 is the base caged execution: when replacing a branded equivalent, confirm the boundary dimensions 50×58×20 mm match exactly — suffix conventions for cage and shell variants differ between makers.
Frequently asked questions
Can a HK5020 needle roller bearing carry axial load?
No. Drawn-cup needle roller bearings like HK5020 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 HK5020 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 (IR40x50x22) so a standard unhardened shaft can be used.
What are the dimensions of a HK5020 needle roller bearing?
A HK5020 drawn-cup needle roller bearing has a 50 mm shaft diameter (Fw, under-roller diameter), 58 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 HK5020 drawn-cup bearing?
Fw is the under-roller diameter — the diameter of the shaft journal on which the needle rollers run directly. For HK5020, 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.
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.