This specification covers the chemical, mechanical, and dimensional requirements for eight grades (Grades O, A, B, C, D, DH, C3, and DH3) of carbon and alloy steel nuts for general structural and mechanical uses on bolts, studs, and other externally threaded parts. Steel materials and nuts shall be manufactured, processed, and formed as appropriate for their respective grades. Each grade of nut shall also conform to individually specified values for chemical composition, hardness, proof load stress, tensile stress areas, nominal size, and style.
Область применения1.1 This specification covers chemical and mechanical requirements for eight grades of carbon and alloy steel nuts for general structural and mechanical uses on bolts, studs, and other externally threaded parts.
Note 1—See Appendix X1 for guidance on suitable application of nut grades.
1.2 The requirements for any grade of nut may, at the supplier's option, and with notice to the purchaser, be fulfilled by furnishing nuts of one of the stronger grades specified herein unless such substitution is barred in the inquiry and purchase order.
1.3 Grades C3 and DH3 nuts have atmospheric corrosion resistance and weathering characteristics comparable to that of the steels covered in Specifications A 242 Note 2—A complete metric companion to Specification A 563 has been developed—A 563M; therefore, no metric equivalents are presented in this specification.
1.4 Terms used in this specification are defined in Terminology F 1789