81136-M bearing: complete specifications & equivalents
The 81136-M is a ISO 104 radial bearing sized 180 x 225 x 34 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 180 mm |
| Outer diameter D | 225 mm |
| Width B | 34 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 270 kN |
| Basic static load rating C0 | 1270 kN |
| Fatigue load limit Pu | 110 kN |
| Reference speed (thermal) | 750 rpm |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3700 g |
| Manufacturer designation | 81136 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 & 81100-series range
| Bore d | 7.087 in |
|---|---|
| Outer diameter D | 8.858 in |
| Width B | 1.339 in |
| ISO bore code | 36 |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in 81100-series | 15 mm |
| Largest outer diameter in 81100-series | 400 mm |
| Width range across 81100-series | 9–63 mm |
| Bore position in 81100-series (smallest first) | 26 of 34 |
| Bore above smallest 81100-series size | 165 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 81136-M model number is decoded
The light 811 series bearing 81136 M carries pure axial load at low to moderate speed: 270 kN dynamic and 1270 kN static across a 180×225 mm washer pair, 34 mm overall height. 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 — 81136 M sits in the light 811 series. The three components are separable and interchangeable within the size: WS shaft washer, K-cage roller set, GS housing washer, all running on flat, square seats; the machined brass M cage is standard for this size. Speed planning separates the 750 r/min thermal reference from the 1,500 r/min mechanical limiting speed. Thrust bearings govern the thermal speed of many vertical arrangements, and oil circulation raises the usable speed substantially above grease values. In vertical shafts let the rotor weight provide the minimum load where possible; otherwise fit a spring pack above the housing washer, and verify the washer face is flooded with oil at first start.
Typical equipment & failure modes
Common applications
- screw jack and lifting screw thrust positions under slow, steady load
- vertical electric motor and pump shafts whose rotor weight loads one bearing
- extruder and injection press screw thrust blocks at low speed
- rolling-mill screwdown mechanisms and press adjusters
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
- oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips
- false brinelling and rust-red witness marks on standby machines under external vibration
- smearing at roller-raceway contacts during unloaded startup before the oil film or preload is established
Selection pitfalls — read before you substitute
- At 180 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 34 mm.
- The 270/1270 kN ratings assume flat, full-support washer seats; a housing face narrower than the 225 mm washer OD invalidates the rating through edge stress.
- Factor A 0.13 is a mounting requirement, not advice: below the minimum axial load the rollers skid at speed — most "mysterious" early thrust failures are unloaded running.
- The separable washers are not interchangeable across series: an 811 and an 812 washer for the same bore differ in OD and height — order WS/GS parts by the full 81136 M size.
- the 750 r/min reference speed is the thermal criterion under load, the 1,500 r/min limiting speed is mechanical and oil lubrication typically raises the usable figure.
- The 270/1270 kN ratings and 3700 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
What ruins a 81136 M in service?
Unloaded running below factor A 0.13 causes skidding; non-square or narrow shoulders fret the washer backs; dry starts and contamination do the rest. Speed ceiling: 1,500 r/min limiting.
Which dimensions does the 81136 M have?
A 81136 M measures 180 mm bore × 225 mm outside diameter × 34 mm width (7.087 × 8.858 × 1.339 in). From SKF catalogue PUB BU/P1 17000: dynamic C 270 kN, static C0 1270 kN, fatigue limit Pu 110 kN, reference speed 750 r/min, limiting speed 1,500 r/min, mass about 3700 g. Raceway diameters Ea 185 mm / Eb 219 mm and minimum load factor A 0.13 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. 81136 M belongs to the light 811 series, 180×225×34 mm.
Are the washers of 81136 M separable?
Yes — shaft washer WS, roller-and-cage set and housing washer GS are separate and interchangeable within the size, but never across series: an 811 and an 812 washer for the same bore differ in OD and height.
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.