Aluminum Back-Up Washer 3/8-Inch Outside Diameter

Aluminum back-up washer with 3/8-inch outside diameter and 1/8-inch inside hole, plain finish, used to distribute load for 1/8-inch rivet fasteners especially on oversized or elongated holes; box contains 500 washers for consistent use in soft materials or repairs, preventing pull-through and improving rivet joint integrity.