NK5-12-TN bearing: complete specifications & equivalents
The NK5-12-TN is a DIN 616 radial bearing sized 5 x 10 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 | 5 mm |
| Outer diameter D | 10 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 2.92 kN |
| Basic static load rating C0 | 2.7 kN |
| Fatigue load limit Pu | 0.29 kN |
| Reference speed (thermal) | 36000 rpm |
| Limiting speed (mechanical) | 40000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3.7 g |
| Manufacturer designation | NK 5/12 TN |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring); 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 & NK-series range
| Bore d | 0.197 in |
|---|---|
| Outer diameter D | 0.394 in |
| Width B | 0.472 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 2.5 mm |
| Smallest bore in NK-series | 5 mm |
| Largest outer diameter in NK-series | 130 mm |
| Width range across NK-series | 10–40 mm |
| Bore position in NK-series (smallest first) | 1 of 46 |
| Bore above smallest NK-series size | 0 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK5-12-TN model number is decoded
SKF's machined-ring needle roller bearings without inner ring include NK 5/12 TN: 5 mm Fw, 10 mm outside diameter, 12 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 5 mm Fw and 12 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 3.7 g catalogue mass and 2.5 mm radial section ((10−5)/2) frame a rating of about 0.58 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 10 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.
Typical equipment & failure modes
Common applications
- piston-pin style pivots in hydraulic pumps
- guide rollers running on hardened tracks
- swing arms and lever pivots with oscillating duty
- cam followers built up from separate components
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
- false brinelling of standby equipment under external vibration
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
Selection pitfalls — read before you substitute
- At Fw 5 mm the rolling elements are under two millimetres long — handle the NK 5/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.
- Do not interchange envelope-identical needle families blindly: NK 5/12 TN shares its 5×10×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- Reference and limiting speeds are different limits: the 36,000 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.
- The 2.92/2.7 kN ratings and 3.7 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Can the NK 5/12 TN run on an unhardened shaft?
No. In this execution the 5 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 NK 5/12 TN be mounted?
Press on the ring faces only with a fitting sleeve, keep everything square to the 5 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs.
What limits the service life of a NK 5/12 TN?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 5 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NK 5/12 TN?
A NK 5/12 TN measures 5 mm bore/Fw × 10 mm outside diameter × 12 mm width (0.197 × 0.394 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.92 kN, static C0 2.7 kN, fatigue limit Pu 0.29 kN, limiting speed 40,000 r/min, reference speed 36,000 r/min, mass about 3.7 g.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring on 2026-09-26. Read our editorial & correction policy.