Features The most common kind of round washer. Flat Washers feature 2 flat surfaces for distributing the force/stress of a nut or bolt. They also help to reduce friction and heat during the installation of a threaded fastener. Flat Washer Type / Flat Washer Washer Basic Material / Stainless Steel System of Measurement / Inch Washer Material Grade / 316 Fastener Finish / Plain Fits Bolt Sizes / 3/8 in Washer Inside Dia. / 25/64 in Washer Outside Dia. / 7/8 in Thickness / 0.05 in Thickness Tolerance / +/-0.010 in Color / Silver Rockwell Hardness / B70 Application / Load Distribution For Use With / Bolts, Nuts, Studs Package Quantity / 100