HK0912 bearing: complete specifications & equivalents
The HK0912 is a ISO 3245 radial bearing sized 9 x 13 x 12 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 9 mm |
| Outer diameter D | 13 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 5.12 kN |
| Basic static load rating C0 | 6.4 kN |
| Fatigue load limit Pu | 0.72 kN |
| Reference speed (thermal) | 18000 rpm |
| Limiting speed (mechanical) | 20000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 4.6 g |
| Manufacturer designation | HK 0912 |
| 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 | 0.354 in |
|---|---|
| Outer diameter D | 0.512 in |
| Width B | 0.472 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 2 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) | 7 of 26 |
| Bore above smallest HK-series size | 6 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HK0912F | NTN | full Dimensions and internal design equivalent — standard interchange. | NTN counterpart on the same 9×13×12 mm envelope with ratings within 10 % — interchange after checking the execution (cage/seal) details on both pages. |
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 HK0912 model number is decoded
The drawn cup bearing HK 0912 gives the smallest radial section of any caged needle bearing with its own outer ring: 9 mm Fw, 13 mm OD and 12 mm width, the shell pressed directly into the housing bore. The designation HK 0912 encodes geometry only — there is no bore code to decode, since the 9 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. The 4.6 g catalogue mass and 2.0 mm radial section ((13−9)/2) frame a rating of about 0.57 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.
Typical equipment & failure modes
Common applications
- spindle clusters of drilling and tapping units
- auto steering gear rack supports
- clutch release mechanisms and cable pulleys
- office equipment and power tool gear trains
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- fretting corrosion of the cup outside diameter in a soft or oversized housing bore
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- corrosion pitting from condensation in intermittently operated machinery
Selection pitfalls — read before you substitute
- On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 13 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.
- Do not interchange envelope-identical needle families blindly: HK 0912 shares its 9×13×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- The 5.12/6.4 kN ratings and 4.6 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Does the HK 0912 need a hardened and ground shaft?
No. In this execution the 9 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.
What mounting mistakes ruin a HK 0912?
Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed.
Is the HK 0912 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 0912 have?
A HK 0912 measures 9 mm bore/Fw × 13 mm outside diameter × 12 mm width (0.354 × 0.512 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.12 kN, static C0 6.4 kN, fatigue limit Pu 0.72 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 4.6 g.
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.