5/16 Flat Washer5/16 USS Washers also called Sellers Standard thread, Franklin Institute thread and American Standard thread washers are a basic standard washer for inch based threaded fasteners. Dimensions Finish Description OD: .875ID: .375Height: .080Washer Pattern: USS Flat WasherRaw: Metal is left untreated. Recommended for those wanting to add their own finish. Black: The part is painted flat black. We recommend this option for parts that have no texturing done to them and for outdoor use.Oil Rubbed Bronze: A wax containing bronze is