Rivet Washer, Standard, Aluminum, Finish Plain, Shape Round, Inside Dia. 1/8 In (0.129), Outside Dia. 0.375 In, Thickness 0.060 In, Thickness Tolerance 0.055 to 0.065 In, For Use With Rivets, Package Quantity 500 Blind Rivet Backup WashersProvide extra support when fastening soft materials and compensate for oversized holes where access to both sides of the work is possible.