NKS75 bearing: complete specifications & equivalents
The NKS75 is a DIN 616 radial bearing sized 75 x 95 x 28 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 75 mm |
| Outer diameter D | 95 mm |
| Width B | 28 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 70.4 kN |
| Basic static load rating C0 | 132 kN |
| Fatigue load limit Pu | 16.6 kN |
| Reference speed (thermal) | 5300 rpm |
| Limiting speed (mechanical) | 6000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 400 g |
| Manufacturer designation | NKS 75 |
| 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 & NKS-series range
| Bore d | 2.953 in |
|---|---|
| Outer diameter D | 3.74 in |
| Width B | 1.102 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 10 mm |
| Smallest bore in NKS-series | 20 mm |
| Largest outer diameter in NKS-series | 95 mm |
| Width range across NKS-series | 20–28 mm |
| Bore position in NKS-series (smallest first) | 17 of 17 |
| Bore above smallest NKS-series size | 55 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKS75 model number is decoded
NKS 75 is a ribbed machined-ring needle roller bearing (no inner ring) sized 75×95×28 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 75 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 75 mm Fw and 28 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. 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. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.
Typical equipment & failure modes
Common applications
- swing arms and lever pivots with oscillating duty
- cam followers built up from separate components
- crank pins and eccentrics where the hardened journal is the raceway
- gearbox planetary and idler gears on hardened pins
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
- Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.
- Do not interchange envelope-identical needle families blindly: NKS 75 shares its 75×95×28 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 5,300 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 70.4/132 kN ratings and 400 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Can the NKS 75 run on an unhardened shaft?
No. In this execution the 75 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 NKS 75 be mounted?
Press on the ring faces only with a fitting sleeve, keep everything square to the 75 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 NKS 75?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 75 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NKS 75?
A NKS 75 measures 75 mm bore/Fw × 95 mm outside diameter × 28 mm width (2.953 × 3.74 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 70.4 kN, static C0 132 kN, fatigue limit Pu 16.6 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 400 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.