This specification covers the chemical, mechanical, and dimensional requirements for hardened steel washers for use with fasteners having nominal thread diameters of M12 through M100. 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 metric hardened steel washers for use with fasteners having nominal thread diameters M12 through M100. 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 325M, A 490M, A 563M and with fasteners of Specification F 568 property classes 8.8 and higher.

1.2 The types of washers covered in this specification are:

1.2.1 Type 1—Washers made of carbon steel.

1.2.2 Type 3—Washers made of steel having atmospheric corrosion resistance and weathering characteristics comparable to that of steels covered in Specifications A 242/A 242M, 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.

1.3 The styles of washers covered in this specification are:

1.3.1 Circular Washers—Circular washers in nominal sizes 12 mm through 100 mm, are suitable for applications where sufficient space exists and angularity permits.

1.3.2 Beveled Washers—Beveled washers are square and rectangular, in nominal sizes 12 mm through 36 mm, with a beveled 1:6 surface for use with American Standard beams and channels.

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

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

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

Note 1—This specification is the metric counterpart of Specification F 436.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.