K50X58X25 bearing: complete specifications & equivalents
The K50X58X25 is a DIN 5402 radial bearing sized 50 x 58 x 25 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 | 58 mm |
| Width B | 25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 41.8 kN |
| Basic static load rating C0 | 81.5 kN |
| Fatigue load limit Pu | 10.2 kN |
| Reference speed (thermal) | 8000 rpm |
| Limiting speed (mechanical) | 9000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 90 g |
| Manufacturer designation | K 50x58x25 |
| Standard | DIN 5402 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies); 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 & K-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 2.283 in |
| Width B | 0.984 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 4 mm |
| Smallest bore in K-series | 3 mm |
| Largest outer diameter in K-series | 63 mm |
| Width range across K-series | 7–32 mm |
| Bore position in K-series (smallest first) | 21 of 22 |
| Bore above smallest K-series size | 47 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the K50X58X25 model number is decoded
In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 50x58x25 appears as a needle roller and cage assembly with complement diameter E 58 mm and width 25 mm — a self-contained roller set that turns a 50 mm shaft and its housing into a complete bearing. The designation numbers of K 50x58x25 state the three machine-seat dimensions — 50 mm journal, 58 mm bore-side complement diameter, 25 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 9,000 r/min limiting speed assumes a precision ground journal and bore. For life calculation, the 41.8/81.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 25 mm narrow cage cannot be relubricated through a closed housing.
Typical equipment & failure modes
Common applications
- hinge and pivot joints in printing and textile machinery
- universal joint crosses on commercial vehicles
- planetary gear pins in compact transmissions
- connecting rods of small compressors where radial height is critical
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
- grease starvation at the roller ends when relubrication intervals are stretched in dirty duty
- hard-particle indentation in unfiltered lubricant
- smearing of rollers and journal during idle periods because the radial section holds too little lubricant
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.
- Do not interchange envelope-identical needle families blindly: K 50x58x25 shares its 50×58×25 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 8,000 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.
- The 41.8/81.5 kN ratings and 90 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only.
Frequently asked questions
Can the K 50x58x25 run on an unhardened shaft?
No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead.
How should the K 50x58x25 be mounted?
Slide the assembly over the ground 50 mm journal with a mounting sleeve, bore the housing to E 58 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded.
What limits the service life of a K 50x58x25?
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 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned.
What are the dimensions and ratings of the K 50x58x25?
A K 50x58x25 measures 50 mm bore/Fw × 58 mm outside diameter × 25 mm width (1.969 × 2.283 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 41.8 kN, static C0 81.5 kN, fatigue limit Pu 10.2 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 90 g.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies on 2026-09-26. Read our editorial & correction policy.