Faucet washers come in a variety of sizes from a variety of vendors, and have done so for many years. These sizes are expressed in different ways as well. I have tried to collect information on how this all works and document it. Note that this table contains some inconsistencies - different vendors give different information, and I've included all of it - this is why 1/4M is listed twice, at two different sizes, for instance. The fractional sizes have suffixes, S for "small", M for "medium", and L for "large". R appears to mean "regular", and is the same as having no suffix, which is why I have R in parenthesis below.
|number size||fractional size||dimension in inches||/32"||/64"||Brasscraft||Korky|