NKIB5910 bearing: complete specifications & equivalents
The NKIB5910 is a DIN 616 radial bearing sized 50 x 72 x 34 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 50 mm |
| Outer diameter D | 72 mm |
| Width B | 34 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 47.3 kN |
| Basic static load rating C0 | 85 kN |
| Fatigue load limit Pu | 10.6 kN |
| Reference speed (thermal) | 7000 rpm |
| Limiting speed (mechanical) | 8000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 390 g |
| Manufacturer designation | NKIB 5910 |
| Standard | DIN 616 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings); 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 & NKIB-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 2.835 in |
| Width B | 1.339 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 11 mm |
| Smallest bore in NKIB-series | 12 mm |
| Largest outer diameter in NKIB-series | 100 mm |
| Width range across NKIB-series | 17.5–45 mm |
| Bore position in NKIB-series (smallest first) | 11 of 15 |
| Bore above smallest NKIB-series size | 38 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKIB5910 model number is decoded
NKIB 5910 is the combined needle roller / three-point contact ball bearings entry for a 50 mm shaft: needle rollers run the radial load while the three-point contact ball set takes axial force in both directions through the three-point contact geometry, in a single machined envelope of 50×72×34 mm. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 595910 the heavy 59 dimension series around the 50 mm bore. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 7,000 r/min thermal reference and 8,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.
Typical equipment & failure modes
Common applications
- gearbox main shafts carrying radial plus one-direction thrust
- worm gear shafts with axial reaction toward the worm
- spindle heads needing compact radial-plus-axial support
- lead-screw and ball-screw support positions
Known failure patterns
- needle edge loading and raceway denting when the shaft deflects beyond the compensation range
- polymer cage deformation when the local temperature exceeds the 120 °C sustained limit
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- brinelling of raceways from impact or pressing force transmitted through the rolling elements
- thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry
Selection pitfalls — read before you substitute
- At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.
- The quoted 47.3/85 kN ratings are SKF catalogue values for this exact execution (NKIB 5910); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.
- 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.
- The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5910 facing the working thrust.
- Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.
- The 47.3/85 kN ratings and 390 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
What mounting mistakes ruin a NKIB 5910?
Press on the ring faces only with a fitting sleeve, keep everything square to the 50 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.
Is the NKIB 5910 sealed?
No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty.
Which dimensions does the NKIB 5910 have?
A NKIB 5910 measures 50 mm bore/Fw × 72 mm outside diameter × 34 mm width (1.969 × 2.835 × 1.339 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 47.3 kN, static C0 85 kN, fatigue limit Pu 10.6 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 390 g. Axial ratings of the ball part: dynamic Ca 7.74 kN (Ca), static C0a 13.7 kN (C0a); three-point contact geometry accepts axial load in both directions.
What does NKIB 5910 mean in SKF part numbering?
NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595910 gives the series and 50 mm bore. The offset (s 30 mm) positions the ball raceway inside the 34 mm overall width.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings on 2026-09-26. Read our editorial & correction policy.