This specification covers the chemical, mechanical, and dimensional requirements for hardened steel washers for use with fasteners having nominal thread diameters of ¼ 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. The types of washers covered here are: Type 1—washers made of carbon steel; and Type 3—washers made of weathering steel. Moreover, the styles of washers covered here are: circular washers, which are suitable for applications where sufficient space exists and angularity permits; beveled washers, which are square and rectangular with a beveled 1:6 surface for use with American Standard beams and channels; and clipped washers, which are circular or beveled for use where space limitations necessitate that one side be clipped. Steels to be used to manufacture the washers shall be produced by the open-hearth, basic-oxygen, or electric-furnace process. Each type and style of washer shall be suitably sampled, and should conform to specified values of chemical composition, Rockwell hardness, inside and outside diameter, thickness, and clipped width.

1.1 This specification covers the chemical, mechanical, and dimensional requirements for hardened steel washers for use with fasteners having nominal thread diameters of ¼ 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:

1.2.1.1 Type 1—Carbon steel.

1.2.1.2 Type 3—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 5.1. 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:

1.2.2.1 Circular—Circular washers in nominal bolt sizes ¼ through 4 in. suitable for applications where sufficient space exists and angularity permits.

1.2.2.2 Beveled—Beveled washers are square or rectangular, in nominal sizes ½ through 1½ in., with a beveled 1 to 6 ratio surface for use with American standard beams and channels.

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

Note 1—A complete metric companion to Specification F 436 has been developed—Specification F 436M; therefore no metric equivalents are presented in this specification.

1.2.2.4 Extra Thick—Extra thick washers are circular washers in nominal sizes ½ through 1½ 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.