Koyo WS-81111 shaft-piloted thrust washer, 55 x 78 x 5 mm

These Koyo WS.811 thrust washers are shaft-piloted metric series washers, made primarily for use with metric series cylindrical roller thrust bearings of series 811. They are made of bearing-quality steel with hardened and precision-ground, lapped-flat raceway surfaces.

A shaft-piloted washer locates on the shaft and clears the housing. The washer should be stationary with respect to the member that pilots it, with no rubbing action between the washer and any other machine member.

The range has 3 sizes with outside diameters from 60 to 95 mm. Koyo bearings are made by JTEKT Corporation.

Where this product is used

• Series 811 cylindrical roller thrust bearings

Features

• Bearing-quality steel, with hardened and precision-ground, lapped-flat raceway surface
• Shaft-piloted: locates on the shaft and clears the housing
• Made primarily for series 811 cylindrical roller thrust bearings
• Bore diameters 40 to 70 mm and outside diameters 60 to 95 mm

Key specifications

Available sizes

Selecting the right option

Choose the washer from the bore diameter, the outside diameter D and the thickness h of the series 811 cylindrical roller thrust bearing it will support. A GS housing-piloted washer of the same size number is the other washer of the pair.

Fitting and use

For a shaft-piloted washer, the catalogue suggests a shaft tolerance of h6 (j6) and a clearance fit in the housing.

Thrust raceway surfaces must be ground to a surface finish of 0.2 µm Ra. Where the backup surfaces are used directly as raceways they must be parallel and hardened to at least 58 HRC, and lower hardness reduces the load ratings. Where that cannot be achieved, use thrust washers. The raceway or the surface backing a washer must be square with the shaft axis and must not be dished or coned.

Related products

Also available from Koyo: the Koyo GS.811 housing-piloted thrust washer range and the Koyo AS thin thrust washer range.