K3X5X7-TN bearing: complete specifications & equivalents
The K3X5X7-TN is a DIN 5402 radial bearing sized 3 x 5 x 7 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 3 mm |
| Outer diameter D | 5 mm |
| Width B | 7 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 1.51 kN |
| Basic static load rating C0 | 1.34 kN |
| Fatigue load limit Pu | 0.134 kN |
| Reference speed (thermal) | 40000 rpm |
| Limiting speed (mechanical) | 45000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 0.3 g |
| Manufacturer designation | K 3x5x7 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 | 0.118 in |
|---|---|
| Outer diameter D | 0.197 in |
| Width B | 0.276 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 1 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) | 1 of 22 |
| Bore above smallest K-series size | 0 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the K3X5X7-TN model number is decoded
SKF lists K 3x5x7 TN in the K series of needle roller and cage assemblies: needle rollers caged at 3×5×7 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 3×5×7 is a boundary plan, not an envelope: the assembly has no rings, so E 5 mm is the needle set diameter the housing bore must match, and the 3 mm journal must be ground and hardened. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 45,000 r/min limiting speed assumes a precision ground journal and bore. Speed planning separates the two ceilings: 40,000 r/min thermal reference and 45,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 3 mm seat. Mounting: grind the 3 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 5 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.
Typical equipment & failure modes
Common applications
- rocker arm and rocker pin pivots on camshafts
- pump and gearbox idler gears running on hardened pins
- hinge and pivot joints in printing and textile machinery
- universal joint crosses on commercial vehicles
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- cage pocket wear and roller skew after sustained operation with too little radial preload
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- rolling-contact fatigue spalling after the rated L10 life
- rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away
Selection pitfalls — read before you substitute
- At Fw 3 mm the rolling elements are under two millimetres long — handle the K 3x5x7 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.
- Reference and limiting speeds are different limits: the 40,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.
- Hardness is load capacity: in families without an inner ring the 3 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 1.51/1.34 kN ratings and 0.3 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
What mounting mistakes ruin a K 3x5x7 TN?
Slide the assembly over the ground 3 mm journal with a mounting sleeve, bore the housing to E 5 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 3x5x7 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 3x5x7 TN have?
A K 3x5x7 TN measures 3 mm bore/Fw × 5 mm outside diameter × 7 mm width (0.118 × 0.197 × 0.276 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 1.51 kN, static C0 1.34 kN, fatigue limit Pu 0.134 kN, limiting speed 45,000 r/min, reference speed 40,000 r/min, mass about 0.3 g.
What does K 3x5x7 TN mean in SKF part numbering?
K = needle roller and cage assembly (DIN 5402); the three figures give Fw 3 mm (shaft journal), E 5 mm (complement outside diameter, matched by the housing bore) and B 7 mm width. TN marks the glass fibre reinforced PA66 cage.
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.