This specification covers round and miscellaneous shape steel plain (flat) washers furnished in an unhardened condition. The washers are intended for general use bolt, nut, and stud applications to provide increased bearing surface, spacing, and to prevent galling. The washers shall be punched from hot-rolled, hot-rolled and pickled, or cold-rolled steel; or shall be machined from bar stock or tubing; or shall be forged. The washers shall also be tumbled, vibrated, or otherwise processed to minimize burrs. These washers may be zinc-coated, hot-dip-coated, cadmium-plated, or zinc-plated by using hot dipping, mechanical deposition, and electroplating processes. Chemical analysis may be conducted in order to determine the composition of washers and a hardness test may also be performed.

1.1 This specification covers round and miscellaneous shape steel plain (flat) washers furnished in an unhardened condition.

1.2 These washers are intended for general use bolt, nut, and stud applications to provide increased bearing surface, spacing, and to prevent galling.

1.3 Unless otherwise specified, washers are furnished with dimensions conforming to B18.21.1, Type A, Table 11.

1.4 Hardened washers for use with heat-treated structural bolts are covered by Specifications F436/F436M.

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

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.