NKIB5902 bearing: complete specifications & equivalents
The NKIB5902 is a DIN 616 radial bearing sized 15 x 28 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 15 mm |
| Outer diameter D | 28 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 11.2 kN |
| Basic static load rating C0 | 15.3 kN |
| Fatigue load limit Pu | 1.83 kN |
| Reference speed (thermal) | 19000 rpm |
| Limiting speed (mechanical) | 22000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 52 g |
| Manufacturer designation | NKIB 5902 |
| 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 | 0.591 in |
|---|---|
| Outer diameter D | 1.102 in |
| Width B | 0.787 in |
| ISO bore code | 02 |
| Radial section height (D−d)/2 | 6.5 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) | 2 of 15 |
| Bore above smallest NKIB-series size | 3 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NKIB5902 model number is decoded
For shafts where a separate thrust bearing would lengthen the assembly, NKIB 5902 integrates needle rollers and an three-point contact ball bearing: 15 mm bore, 28 mm OD, 20 mm overall width including the ball set offset. The NKIB 5902 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 15 mm; the 20 mm width covers both the roller cage and the offset ball set (s offset 18 mm). NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 11.2 kN, radial C0 15.3 kN, axial dynamic 2.27 kN (Ca) and axial static 2.37 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 20 mm wide unit can lift the seals of adjacent components.
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
- 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
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- electrical erosion on VFD-driven shafts without brush or insulated mounting
- thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor
Selection pitfalls — read before you substitute
- On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.
- Do not interchange envelope-identical needle families blindly: NKIB 5902 shares its 15×28×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.
- Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.
- Do not treat the axial rating 2.27 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.
- 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 5902 facing the working thrust.
- The 11.2/15.3 kN ratings and 52 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 limits the service life of a NKIB 5902?
Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 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.
What are the dimensions and ratings of the NKIB 5902?
A NKIB 5902 measures 15 mm bore/Fw × 28 mm outside diameter × 20 mm width (0.591 × 1.102 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.2 kN, static C0 15.3 kN, fatigue limit Pu 1.83 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 52 g. Axial ratings of the ball part: dynamic Ca 2.27 kN (Ca), static C0a 2.37 kN (C0a); three-point contact geometry accepts axial load in both directions.
How is the NKIB 5902 designation read?
NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595902 gives the series and 15 mm bore. The offset (s 18 mm) positions the ball raceway inside the 20 mm overall width.
Can the NKIB 5902 run on an unhardened shaft?
The needle roller part of the NKIB 5902 rides directly on the 15 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.