That is a good question...because the part was so small we were not able to test carbon content and of course the reported chemistry matches 302 as well. 304 and 302 have increased chromium and nickel for corrosion resistance, toughness and ductility, but increasing the carbon in the 302...
Does anyone know of a manufacturer of 304 SS Belleville Washers for a #6 Bolt? Below are the actual measurements taken from the Belleville Washer that I need to replace.
.275 OD
.139 ID
.015 THK.
.025 Overall Height