These AN flat washers by Pro-werks are flat washers made of non-hardened steel and are cadmium plated (gold in color). They are smaller in outside diameter than flat washers that most of us are familiar with in the industrial world. Their primary purpose in the aircraft world is to provide a smooth bearing surface under a hex nut allowing for index alignment of cotter pin holes or as shims to obtain the proper grip length needed on the fastener. Performance builders often select AN washers for applications where space availability is limited and/or to also save weight.
Conveniently packaged in quantities of 100.