This practice covers a system for designating cast and wrought nonferrous metals and alloys. It was originally adopted for light metals and alloys that are cast and wrought and later extended to heavier base-metal die-casting alloys. Chemical composition limits serve as the basis for the Unified Numbering System (UNS) designations. The temper designations used for all metal forms, except for ingots, follow the alloy designation.

1.1 This practice covers a system for designating die-casting alloys of zinc, tin and lead. Those designations currently being used in specifications under the jurisdiction of Committees B02 on Nonferrous Metals and are listed in Appendix Table X2.1.

1.1.1 The alloy designations now being used in Committee B07 specifications for aluminum and aluminum-alloy wrought and cast products conform to ANSI H35.1. Alloys formerly codified by this practice and the corresponding ANSI designations are shown in Tables X3.1 and X3.2 of the Appendix for legacy purposes.

1.1.2 The alloy designations now being used in Committee B07 specifications for magnesium and magnesium-alloy wrought and cast products conform to Practice B951, as indicated in Appendix X4. Alloy designations formerly codified by this practice are no longer relevant.

1.2 The equivalent Unified Numbering System (UNS) alloy designations shown in the appendixes are in accordance with Practice E527.