HK1312 bearing: complete specifications & equivalents
The HK1312 is a ISO 3245 radial bearing sized 13 x 19 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 | 13 mm |
| Outer diameter D | 19 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 6.6 kN |
| Basic static load rating C0 | 8 kN |
| Fatigue load limit Pu | 0.915 kN |
| Reference speed (thermal) | 16000 rpm |
| Limiting speed (mechanical) | 17000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 10.5 g |
| Manufacturer designation | HK 1312 |
| 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 | 0.512 in |
|---|---|
| Outer diameter D | 0.748 in |
| Width B | 0.472 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 3 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) | 10 of 26 |
| Bore above smallest HK-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| HK1312 | 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 HK1312 model number is decoded
SKF supplies HK 1312 for housings where machining an outer-ring pocket is uneconomical: the 19 mm shell broached from sheet steel press-fits into a plain bore and runs a 13 mm hardened shaft. SKF's HK numbering puts the shaft size first: 13 → Fw 13 mm (the ground, hardened journal), 12 → width 12 mm, with the 19 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. 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. The 10.5 g catalogue mass and 3.0 mm radial section ((19−13)/2) frame a rating of about 0.51 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
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- 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
- rolling-contact fatigue spalling after the rated L10 life
Selection pitfalls — read before you substitute
- On a 13 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- Hardness is load capacity: in families without an inner ring the 13 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.
- The quoted 6.6/8 kN ratings are SKF catalogue values for this exact execution (HK 1312); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 6.6/8 kN ratings and 10.5 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
How is the HK 1312 designation read?
HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 13 mm, the last two the width 12 mm, the shell OD 19 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage.
Can the HK 1312 run on an unhardened shaft?
No. In this execution the 13 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.
How should the HK 1312 be mounted?
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.
What limits the service life of a HK 1312?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 13 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
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.