K9X12X10-TN bearing: complete specifications & equivalents
The K9X12X10-TN is a DIN 5402 radial bearing sized 9 x 12 x 10 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 | 12 mm |
| Width B | 10 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 4.4 kN |
| Basic static load rating C0 | 5.2 kN |
| Fatigue load limit Pu | 0.57 kN |
| Reference speed (thermal) | 30000 rpm |
| Limiting speed (mechanical) | 34000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1.5 g |
| Manufacturer designation | K 9x12x10 TN |
| Standard | DIN 5402 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies); 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 & K-series range
| Bore d | 0.354 in |
|---|---|
| Outer diameter D | 0.472 in |
| Width B | 0.394 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 1.5 mm |
| Smallest bore in K-series | 3 mm |
| Largest outer diameter in K-series | 63 mm |
| Width range across K-series | 7–32 mm |
| Bore position in K-series (smallest first) | 7 of 22 |
| Bore above smallest K-series size | 6 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the K9X12X10-TN model number is decoded
SKF lists K 9x12x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 9×12×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 9 (shaft journal), E 12 (assembly outside diameter) and B 10 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. The 1.5 g catalogue mass and 1.5 mm radial section ((12−9)/2) frame a rating of about 0.49 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.
Typical equipment & failure modes
Common applications
- pump and gearbox idler gears running on hardened pins
- hinge and pivot joints in printing and textile machinery
- universal joint crosses on commercial vehicles
- planetary gear pins in compact transmissions
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- polymer cage deformation when the local temperature exceeds the 120 °C sustained limit
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- brinelling of raceways from impact or pressing force transmitted through the rolling elements
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
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 12 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: K 9x12x10 TN shares its 9×12×10 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- The 4.4/5.2 kN ratings and 1.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Does the K 9x12x10 TN 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 K 9x12x10 TN?
Slide the assembly over the ground 9 mm journal with a mounting sleeve, bore the housing to E 12 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded.
Is the K 9x12x10 TN sealed?
No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty.
Which dimensions does the K 9x12x10 TN have?
A K 9x12x10 TN measures 9 mm bore/Fw × 12 mm outside diameter × 10 mm width (0.354 × 0.472 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.4 kN, static C0 5.2 kN, fatigue limit Pu 0.57 kN, limiting speed 34,000 r/min, reference speed 30,000 r/min, mass about 1.5 g.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies on 2026-09-26. Read our editorial & correction policy.