NK65-35 bearing: complete specifications & equivalents
The NK65-35 is a DIN 616 radial bearing sized 65 x 78 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 | 65 mm |
| Outer diameter D | 78 mm |
| Width B | 35 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 58.3 kN |
| Basic static load rating C0 | 146 kN |
| Fatigue load limit Pu | 18.3 kN |
| Reference speed (thermal) | 6300 rpm |
| Limiting speed (mechanical) | 7000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 310 g |
| Manufacturer designation | NK 65/35 |
| 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 | 2.559 in |
|---|---|
| Outer diameter D | 3.071 in |
| Width B | 1.378 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 6.5 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) | 35 of 46 |
| Bore above smallest NK-series size | 60 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK65-35 model number is decoded
In SKF catalogue PUB BU/P1 17000, NK 65/35 designates a flanged, machined outer ring filled with needle rollers and a cage for a 65 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 65 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 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. For life calculation, the 58.3/146 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. 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
- guide rollers running on hardened tracks
- 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
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after overload events
- polymer cage deformation when the local temperature exceeds the 120 °C sustained limit
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- corrosion pitting from condensation in intermittently operated machinery
- rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away
Selection pitfalls — read before you substitute
- Above 50 mm bore, thermal growth matters: the 65 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.
- 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 58.3/146 kN ratings and 310 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
How is the NK 65/35 designation read?
NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 65 mm and width 35 mm, OD 78 mm comes from the dimension series, and the flanged outer ring retains the caged rollers.
Can the NK 65/35 run on an unhardened shaft?
No. In this execution the 65 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 65/35 be mounted?
Press on the ring faces only with a fitting sleeve, keep everything square to the 65 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 65/35?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 65 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned.
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.