How are the dimensional specifications of stainless steel flat washers determined?

Stainless steel flat washers typically adhere to the same dimensional standards as plain steel flat washers, which are governed by ASME B18.21.1. Under ASME B18.21.1, the dimensional tolerances for plain washers are specified according to two types: Type A and Type B.

1. Type A: Type A washers have two series sizes: narrow and wide. The narrow series typically has smaller thickness and outside diameter compared to the wide series.

2. Type B: Type B washers have three series sizes: narrow, regular, and wide. The narrow series tends to have smaller dimensions compared to the regular and wide series.

While the differences between the series are minimal, depending on the manufacturer or supplier of the stainless steel washers, they may be supplied in any of these series. Therefore, if the application demands precise washer dimensions, it may be necessary to specify the desired type and series. This ensures that the washers provided meet the required specifications for the application.