AN Flat Washers

AN flat washers are a military spec and have consistent inside and outside diameters as well as consistent thickness compared to ordinary flat washers found at a hardware store.

AN flat washers are used under hex nuts to provide a smooth bearing surface, as shims to obtain the correct grip length for a bolt and nut assembly, and to adjust the position of AN310 and AN320 castle nuts with respect to drilled cotter pin holes in bolts and clevis pins.