Shim rings are flat washers used in combination when axial clearance must be offset. This could be on a shaft where there is a locking ring/bearing, between which clearance must be offset. By combining washers of different thicknesses you can precisely offset the clearance.
Shims refer to a broad class of specialty flat washers that are used for positioning and spacing. While shims look like flat washers they are different in that shims are typically made using more precise materials and production techniques.
Axial play resulting from manufacturing tolerances can be rigidly reduced by using various thicknesses of shim washers.
Compensation for axial play
Standard : DIN 988
Material : Stainless Steel AISI 304
Range : 0.1mm to 1mm