A beveled (rocking) washer equalizes form inaccuracies

Often in precision assembly (especially in tooling) we find difficulties to tighten components with form inaccuracies. In order to minimize total inaccuracies we have to grind all surfaces, which in turn increases the cost.

A component that increases the use of standard parts is the beveled washer. The beveled washer has exactly what its name says: its mating surfaces are beveled. This shape (see figure) permits the washer to bevel around a small land, equalizes this way the form inaccuracies of mating components. The size of land is about 5% of washer external diameter, and the bevel from 2° to 5°. The lands are ground (or polished). The washer material is case hardening steel (50-55 HRC).

With such washers we tight from grind wheels (high speed rotary machinery equipment) to clamping and metrology fixtures.