Specifies nuts in diameters M1.6 to M64 and six property classes. Specifies dimensions, material, mechanical properties and marking requirements, and includes recommended methods of test for mechanical properties. Primarily covers carbon steel nuts but dimensional requirements also apply to non-ferrous and stainless steel nuts. Appendices include nut/fastener combinations, dimensions of non-preferred sizes, method for checking squareness of thread, dimensions of nuts from M72 to M150, basis for derivation of tolerances, notes on sizes, a suggested sampling plan, proof loads for galvanized steel nuts, and complete designation for ordering purposes.