NKIA5910 bearing: complete specifications & equivalents
The NKIA5910 is a DIN 616 radial bearing sized 50 x 72 x 30 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 | 30 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 | 380 g |
| Manufacturer designation | NKIA 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 & NKIA-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 2.835 in |
| Width B | 1.181 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 11 mm |
| Smallest bore in NKIA-series | 12 mm |
| Largest outer diameter in NKIA-series | 100 mm |
| Width range across NKIA-series | 16–40 mm |
| Bore position in NKIA-series (smallest first) | 11 of 15 |
| Bore above smallest NKIA-series size | 38 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKIA5910 model number is decoded
In SKF catalogue PUB BU/P1 17000, NKIA 5910 designates a combined bearing of the combined needle roller / angular contact ball bearings: caged needle rollers for the 50 mm radial seat share a shaft with an integral angular contact ball set rated 7.74 kN (Ca) axially. The NKIA 5910 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 50 mm; the 30 mm width covers both the roller cage and the offset ball set (offset per catalogue s column). 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. Mounting: press on the inner ring faces only — the ball set offset (a catalogue-listed offset) makes the unit sensitive to bending; support both rings square to the 50 mm seat and never drive through the rolling elements.
Typical equipment & failure modes
Common applications
- spindle heads needing compact radial-plus-axial support
- lead-screw and ball-screw support positions
- pump rotors with hydraulic axial pull
- bevel gear shafts with moderate axial force
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
- 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.
- 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.
- 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.
- Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.
- The 47.3/85 kN ratings and 380 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
Can the NKIA 5910 run on an unhardened shaft?
The needle roller part of the NKIA 5910 rides directly on the 50 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement.
How should the NKIA 5910 be mounted?
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.
What limits the service life of a NKIA 5910?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the NKIA 5910?
A NKIA 5910 measures 50 mm bore/Fw × 72 mm outside diameter × 30 mm width (1.969 × 2.835 × 1.181 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 380 g. Axial ratings of the ball part: dynamic Ca 7.74 kN (Ca), static C0a 13.7 kN (C0a); angular contact geometry leans axial capacity toward one direction.
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.