81230-M bearing: complete specifications & equivalents
The 81230-M is a ISO 104 radial bearing sized 150 x 215 x 50 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 150 mm |
| Outer diameter D | 215 mm |
| Width B | 50 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 465 kN |
| Basic static load rating C0 | 1900 kN |
| Fatigue load limit Pu | 170 kN |
| Reference speed (thermal) | 630 rpm |
| Limiting speed (mechanical) | 1300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7200 g |
| Manufacturer designation | 81230 M |
| Standard | ISO 104 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical roller thrust bearings |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical roller thrust bearings) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical roller thrust 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 & 81200-series range
| Bore d | 5.906 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.969 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 32.5 mm |
| Smallest bore in 81200-series | 30 mm |
| Largest outer diameter in 81200-series | 420 mm |
| Width range across 81200-series | 16–95 mm |
| Bore position in 81200-series (smallest first) | 19 of 28 |
| Bore above smallest 81200-series size | 120 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 81230-M model number is decoded
SKF supplies 81230 M as a separable thrust bearing: the 150 mm shaft washer (WS), the machined brass M cage holding short cylindrical rollers, and the 215 mm housing washer (GS) can be ordered and mounted individually. SKF thrust-roller numbering mirrors the ball 511/512 plan with 811/812: 812 is the higher (heavier) section per bore, and 893/894 are the very heavy series — 81230 M sits in the heavy 812 series. The bearing takes thrust in one direction only — reverse loads lift the roller set off its track; arrange a mirrored second bearing for reversing duty, and keep the applied load above factor A 0.29. Static safety matters for shock duty: compare peak axial force against C0 1900 kN with the application's static factor, since crane hooks and screw positions see their worst load at zero or low speed. Mounting: locate the shaft washer on the 150 mm seat (it rotates and takes an interference fit), leave the housing washer a sliding fit in the 215 mm bore, and check the stack can tilt freely before clamping.
Typical equipment & failure modes
Common applications
- rolling-mill screwdown mechanisms and press adjusters
- slewing and turntable pivots with predominantly axial force
- crane hook crossheads carrying pure hook thrust while the hook swivels
- screw jack and lifting screw thrust positions under slow, steady load
Known failure patterns
- roller skidding and raceway glazing once the thrust falls below the catalogue minimum axial load (factor A)
- housing-washer rotation scored into an unmachined or loose seating face
- abrasive paste forming as dust bypasses the housing seals into the open washer set
- hard-particle indentation where oil or grease filtration is inadequate
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
Selection pitfalls — read before you substitute
- At 150 mm bore the washers are too stiff to conform to a non-square seat: machine the shoulders parallel or the roller ends concentrate load into a narrow stripe across 50 mm.
- The 465/1900 kN ratings assume flat, full-support washer seats; a housing face narrower than the 215 mm washer OD invalidates the rating through edge stress.
- Factor A 0.29 is a mounting requirement, not advice: below the minimum axial load the rollers skid at speed — most "mysterious" early thrust failures are unloaded running.
- Keep the machined brass M cage out of chemical contact with aggressive EP additives beyond its compatibility list; cage damage here redistributes rollers and destroys the washer in hours.
- Do not substitute a thrust ball bearing of the same ISO envelope by rating alone: the cylindrical rollers of 81230 M need different minimum load and lubrication despite the shared 150×215 mm outline.
- The 465/1900 kN ratings and 7200 g mass are SKF catalogue values transcribed from ch. 11.1 of PUB BU/P1 17000 (PDF table page 892); mounting data — Ea/Eb raceway diameters and the minimum load factor A — appears in the running text because the structured record carries the boundary envelope only.
Frequently asked questions
Can a thrust ball bearing replace the 81230 M?
They share ISO boundary outlines (e.g. 511 vs 811), but the roller bearing needs a higher minimum axial load and different lubrication, and its C/C0 figures are not interchangeable — re-run the selection before substituting.
What ruins a 81230 M in service?
Unloaded running below factor A 0.29 causes skidding; non-square or narrow shoulders fret the washer backs; dry starts and contamination do the rest. Speed ceiling: 1,300 r/min limiting.
Which dimensions does the 81230 M have?
A 81230 M measures 150 mm bore × 215 mm outside diameter × 50 mm width (5.906 × 8.465 × 1.969 in). From SKF catalogue PUB BU/P1 17000: dynamic C 465 kN, static C0 1900 kN, fatigue limit Pu 170 kN, reference speed 630 r/min, limiting speed 1,300 r/min, mass about 7200 g. Raceway diameters Ea 162 mm / Eb 210 mm and minimum load factor A 0.29 guide the seat design.
What is the difference between 811 and 812 series?
811 is the light section and 812 the higher, heavier section for the same bore; 893/894 are the extra-heavy series. 81230 M belongs to the heavy 812 series, 150×215×50 mm.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 11.1 cylindrical roller thrust bearings on 2026-09-27. Read our editorial & correction policy.