The Unified Numbering System Copper
The Unified Numbering System (UNS) is the accepted alloy designation system in North America for wrought and cast copper and copper alloy products. The three-digit system developed by the U.S. copper and brass industry was expanded to five digits following the prefix letter C and made part of the Unified Numbering System for Metals and Alloys.
In the designation system, numbers from C10000 through C79999 denote wrought alloys. Cast alloys are numbered from C80000 through C99999. Within these two categories, the compositions are grouped into the following families of coppers and copper alloys: