3/8" x 1-1/4" Stainless Fender Washer
Large outside diameter flat washers used under the head of a bolt or nut to distribute the forces applied when tightening. Made from austenitic stainless steels. It contains chromium creating an invisible surface film that resists oxidation making the metal corrosion resistant. If the surface layer is damaged, it rebuilds itself in the presence of oxygen.