This specification covers the chemical, mechanical and dimensional requirements for hardened steel washers for use with fasteners having nominal thread diameters of 1/4 through 4 in. These washers are intended for general-purpose, mechanical and structural use with bolts, nuts studs and other internally and externally threaded fasteners. These washers are suitable for use with fasteners covered in Specifications A325, A449 and 4490.\nThe styles of covered washers are:\nCircular: washers in nominal bolt sizes 1/4 through 4 in, suitable for applications where sufficient space exists and angularity permits.\nClipped : these washers are circular or beveled for use where space limitations necessitate that one side be clipped.\nExtra thick: these washers are circular washers in nominal sizes 1/2 through 1-1/2 in., with a nominal thickness of 5/16 in. suitable for structural applications with oversized holes.