1.1 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 A 325, A 354, A 449, and A 490.

1.2 The washers are designated by type denoting the material and by style denoting the shape.

1.2.1 The types of washers covered are:

Carbon steel.

Weathering steel. Atmospheric corrosion resistance and weathering characteristics are comparable to that of steels covered in Specifications A 588/A 588M and A 709/A 709M. The atmospheric corrosion resistance of these steels is substantially better than that of carbon steel with or without copper addition. See . When properly exposed to the atmosphere, these steels can be used bare (uncoated) for many applications.

1.2.2 The styles of washers covered are:

Circular washers in nominal bolt sizes 1/4 through 4 in. suitable for applications where sufficient space exists and angularity permits.

Beveled washers are square or rectangular, in nominal sizes 1/2 through 11/2 in., with a beveled 1 to 6 ratio surface for use with American standard beams and channels.

Clipped washers are circular or beveled for use where space limitations necessitate that one side be clipped.

A complete metric companion to Specification F 436 has been developed-Specification F 436M; therefore no metric equivalents are presented in this specification.

Extra thick washers are circular washers in nominal sizes 1/2through 11/2 in., with a nominal thickness of 5/16 in. suitable for structural applications with oversized holes.

1.3 Terms used in this specification are defined in Terminology F 1789 unless otherwise defined herein.