The UNS for Metals and Alloys provides a means of correlating many internationally used metal and alloy numbering systems administered by societies, trade associations, and individual users and producers of metals and alloys. Jointly developed by ASTM International and the Society of Automotive Engineers (SAE), it provides the uniformity necessary for efficient indexing, record keeping, data storage and retrieval, and cross-referencing.

The 12th edition has been updated to include more than 5,600 designations, 4,100 representative specification cross references, and 15,350 trade names.

This edition includes:
• Introduction
• Index to UNS Designations by Base Elements
• Listing of UNS Numbers assigned-to date, with a description of each material covered and references to documents in which the same or similar materials are described
• Cross-index of commonly known documents which describe materials which are the same as or similar to those covered by UNS numbers
• Index of Common Trade Designations
• Reprint of the J1086/ASTM E527 Standard "Recommended Practice for Numbering Metals and Alloys"

Cross-references include specifications from these organizations:
• AA (Aluminum Association)
• ACI (Steel Founders of America)
• AISI (American Iron and Steel Institute)
• AMS (SAE Aerospace Materials Specifications)
• ASME (American Society of Mechanical Engineers)
• ASTM International
• AWS (American Welding Society)
• QQ (Federal Specification)
• MILS (Military Specification)