K6X9X8-TN bearing: complete specifications & equivalents
The K6X9X8-TN is a DIN 5402 radial bearing sized 6 x 9 x 8 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 6 mm |
| Outer diameter D | 9 mm |
| Width B | 8 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 2.55 kN |
| Basic static load rating C0 | 2.36 kN |
| Fatigue load limit Pu | 0.25 kN |
| Reference speed (thermal) | 34000 rpm |
| Limiting speed (mechanical) | 38000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 0.8 g |
| Manufacturer designation | K 6x9x8 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 | 0.236 in |
|---|---|
| Outer diameter D | 0.354 in |
| Width B | 0.315 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) | 4 of 22 |
| Bore above smallest K-series size | 3 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the K6X9X8-TN model number is decoded
For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 6x9x8 TN: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 6 × E 9 × B 8 mm. In the K code K 6x9x8 TN, Fw×E×B reads directly as journal 6 mm, complement diameter 9 mm and cage width 8 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 8 mm narrow cage cannot be relubricated through a closed housing.
Typical equipment & failure modes
Common applications
- universal joint crosses on commercial vehicles
- planetary gear pins in compact transmissions
- connecting rods of small compressors where radial height is critical
- rocker arm and rocker pin pivots on camshafts
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- cage pocket wear and roller skew after sustained operation with too little radial preload
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- electrical erosion on VFD-driven shafts without brush or insulated mounting
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
Selection pitfalls — read before you substitute
- At Fw 6 mm the rolling elements are under two millimetres long — handle the K 6x9x8 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.
- 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.
- 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.
- The 2.55/2.36 kN ratings and 0.8 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
Can the K 6x9x8 TN run on an unhardened shaft?
No. In this execution the 6 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 K 6x9x8 TN be mounted?
Slide the assembly over the ground 6 mm journal with a mounting sleeve, bore the housing to E 9 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded.
What limits the service life of a K 6x9x8 TN?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 6 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 1.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the K 6x9x8 TN?
A K 6x9x8 TN measures 6 mm bore/Fw × 9 mm outside diameter × 8 mm width (0.236 × 0.354 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.55 kN, static C0 2.36 kN, fatigue limit Pu 0.25 kN, limiting speed 38,000 r/min, reference speed 34,000 r/min, mass about 0.8 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.