These Round, Military Specification Flat Washers are approved for use in tough, military applications. - Made from 18-8 stainless steel, they 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. Washer Basic Material / Stainless Steel System of Measurement / Inch Washer Material Grade / 18-8 Fastener Finish / Plain Fits Bolt Sizes / 5/8 in Washer Inside Dia. / 11/16 in Washer Outside Dia. / 1 3/4 in Thickness / 0.108 in to 0.160 in Rockwell Hardness / B70 For Use With / Screws and Studs Washer Standards / MS15795 Package Weight / 0.2 Package Quantity / 5