NK110-40 bearing: complete specifications & equivalents
The NK110-40 is a DIN 616 radial bearing sized 110 x 130 x 40 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 110 mm |
| Outer diameter D | 130 mm |
| Width B | 40 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 123 kN |
| Basic static load rating C0 | 305 kN |
| Fatigue load limit Pu | 37.5 kN |
| Reference speed (thermal) | 3600 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 830 g |
| Manufacturer designation | NK 110/40 |
| 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 | 4.331 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 1.575 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 10 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) | 46 of 46 |
| Bore above smallest NK-series size | 105 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NK110-40 model number is decoded
NK 110/40 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 110 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 110 mm Fw and 40 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. Catalogue mass 830 g at 110×130×40 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. 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
- 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
- piston-pin style pivots in hydraulic pumps
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 110 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 110 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 123/305 kN ratings are SKF catalogue values for this exact execution (NK 110/40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- The 123/305 kN ratings and 830 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
How should the NK 110/40 be mounted?
Press on the ring faces only with a fitting sleeve, keep everything square to the 110 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 110/40?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 110 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 NK 110/40?
A NK 110/40 measures 110 mm bore/Fw × 130 mm outside diameter × 40 mm width (4.331 × 5.118 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 123 kN, static C0 305 kN, fatigue limit Pu 37.5 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 830 g.
How is the NK 110/40 designation read?
NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 110 mm and width 40 mm, OD 130 mm comes from the dimension series, and the flanged outer ring retains the caged rollers.
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.