HK2538 bearing: complete specifications & equivalents
The HK2538 is a ISO 3245 radial bearing sized 25 x 32 x 38 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 25 mm |
| Outer diameter D | 32 mm |
| Width B | 38 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 33 kN |
| Basic static load rating C0 | 65.5 kN |
| Fatigue load limit Pu | 8 kN |
| Reference speed (thermal) | 9500 rpm |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 64 g |
| Manufacturer designation | HK 2538 |
| Standard | ISO 3245 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & HK-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 1.26 in |
| Width B | 1.496 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 3.5 mm |
| Smallest bore in HK-series | 3 mm |
| Largest outer diameter in HK-series | 68 mm |
| Width range across HK-series | 6–38 mm |
| Bore position in HK-series (smallest first) | 18 of 26 |
| Bore above smallest HK-series size | 22 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HK2538 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the HK2538 model number is decoded
Ordering number HK 2538 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 25 for the 25 mm under-roller diameter and 38 for the 38 mm width. The designation HK 2538 encodes geometry only — there is no bore code to decode, since the 25 mm Fw is printed directly in the first digits and the cup width 38 mm in the last two. Double-row execution: two rows of needle rollers share the 25 mm Fw seat in one cup — double the capacity of the single-row HK at the same 32×38 mm envelope. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 64 g at 25×32×38 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 38 mm section.
Typical equipment & failure modes
Common applications
- office equipment and power tool gear trains
- steering column and pedal-box pivots in passenger cars
- idler gears and pulleys in small appliance drives
- spindle clusters of drilling and tapping units
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- electrical erosion on VFD-driven shafts without brush or insulated mounting
Selection pitfalls — read before you substitute
- On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- The quoted 33/65.5 kN ratings are SKF catalogue values for this exact execution (HK 2538); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.
- The 33/65.5 kN ratings and 64 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Is the HK 2538 sealed?
No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill.
Which dimensions does the HK 2538 have?
A HK 2538 measures 25 mm bore/Fw × 32 mm outside diameter × 38 mm width (0.984 × 1.26 × 1.496 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 33 kN, static C0 65.5 kN, fatigue limit Pu 8 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 64 g.
What does HK 2538 mean in SKF part numbering?
HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 25 mm, the last two the width 38 mm, the shell OD 32 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage.
Does the HK 2538 need a hardened and ground shaft?
No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings on 2026-09-26. Read our editorial & correction policy.