NK75-35 bearing: complete specifications & equivalents
The NK75-35 is a DIN 616 radial bearing sized 75 x 92 x 35 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 | 92 mm |
| Width B | 35 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 74.8 kN |
| Basic static load rating C0 | 170 kN |
| Fatigue load limit Pu | 21.2 kN |
| Reference speed (thermal) | 5300 rpm |
| Limiting speed (mechanical) | 6000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 450 g |
| Manufacturer designation | NK 75/35 |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 3.622 in |
| Width B | 1.378 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 8.5 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) | 39 of 46 |
| Bore above smallest NK-series size | 70 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK75-35 model number is decoded
SKF's machined-ring needle roller bearings without inner ring include NK 75/35: 75 mm Fw, 92 mm outside diameter, 35 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 75 mm Fw and 35 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. Selection arithmetic: C 74.8 kN against C0 170 kN gives a C0/C ratio of 2.27, and the 21.2 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.
Typical equipment & failure modes
Common applications
- crank pins and eccentrics where the hardened journal is the raceway
- gearbox planetary and idler gears on hardened pins
- piston-pin style pivots in hydraulic pumps
- guide rollers running on hardened tracks
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
- rolling-contact fatigue spalling after the rated L10 life
- 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.
- Hardness is load capacity: in families without an inner ring the 75 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 quoted 74.8/170 kN ratings are SKF catalogue values for this exact execution (NK 75/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 74.8/170 kN ratings and 450 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 NK 75/35 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 NK 75/35 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 NK 75/35?
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 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NK 75/35?
A NK 75/35 measures 75 mm bore/Fw × 92 mm outside diameter × 35 mm width (2.953 × 3.622 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 74.8 kN, static C0 170 kN, fatigue limit Pu 21.2 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 450 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.