NKIA5906 bearing: complete specifications & equivalents
The NKIA5906 is a DIN 616 radial bearing sized 30 x 47 x 23 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 30 mm |
| Outer diameter D | 47 mm |
| Width B | 23 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 25.5 kN |
| Basic static load rating C0 | 39 kN |
| Fatigue load limit Pu | 4.65 kN |
| Reference speed (thermal) | 11000 rpm |
| Limiting speed (mechanical) | 13000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 150 g |
| Manufacturer designation | NKIA 5906 |
| 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 | 1.181 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.906 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 8.5 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) | 7 of 15 |
| Bore above smallest NKIA-series size | 18 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKIA5906 model number is decoded
For shafts where a separate thrust bearing would lengthen the assembly, NKIA 5906 integrates needle rollers and an angular contact ball bearing: 30 mm bore, 47 mm OD, 23 mm overall width including the ball set offset. In SKF nomenclature NKIA denotes the combined construction and 595906 the series/bore; the ball raceway sits offset on the inner ring, which is why the 23 mm overall width is greater than a plain needle bearing of the same bore. Execution notes: the ball set runs on a raceway offset by a catalogue-listed offset from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Selection arithmetic for the combined unit: radial C 25.5 kN, radial C0 39 kN, axial dynamic 4.54 kN (Ca) and axial static 6.32 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. 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
- 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
- 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
- abrasive paste formation from dust ingressing past open ends without effective housing seals
- brinelling of raceways from impact or pressing force transmitted through the rolling elements
- thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor
Selection pitfalls — read before you substitute
- At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.
- The quoted 25.5/39 kN ratings are SKF catalogue values for this exact execution (NKIA 5906); 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 NKIA 5906 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 25.5/39 kN ratings and 150 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
Is the NKIA 5906 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 NKIA 5906 have?
A NKIA 5906 measures 30 mm bore/Fw × 47 mm outside diameter × 23 mm width (1.181 × 1.85 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 150 g. Axial ratings of the ball part: dynamic Ca 4.54 kN (Ca), static C0a 6.32 kN (C0a); angular contact geometry leans axial capacity toward one direction.
What does NKIA 5906 mean in SKF part numbering?
NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595906 gives the series and 30 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 23 mm overall width.
Does the NKIA 5906 need a hardened and ground shaft?
The needle roller part of the NKIA 5906 rides directly on the 30 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.
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.