Copper alloy names can be confusing because a family label, a UNS number and a purchase specification answer different questions. The family and UNS range are useful for an initial lookup, but they do not tell you every detail needed to buy, machine, weld or certify a part. This reference separates the broad wrought and cast families so you can identify where a designation sits before checking the full material specification.

Copper and copper alloy classification

How to read a UNS range

UNS designations use the letter C followed by five digits for copper and copper alloys. The broad ranges in the table group materials by family and distinguish wrought product designations from cast product designations. For example, wrought coppers occupy C10100 through C15999, while cast coppers are grouped in C80000 through C81399. The ranges are classification guides; the exact registered alloy is identified by its individual UNS designation and associated product information.

Wrought material has been mechanically worked into product such as sheet, strip, rod, tube or bar. Cast products are shaped by pouring molten metal into a mold. Those routes affect which alloy designations and product specifications apply. Do not use a cast range to identify a wrought product, or assume that a family name alone confirms a particular manufacturing route.

Common copper alloy families

The wrought ranges include coppers, high-copper alloys, brasses, bronzes, copper nickels and nickel silvers. The names describe broad composition families: zinc is the principal alloying element in brasses; bronze families include several different alloy systems; copper nickels contain nickel; and nickel silvers are copper-nickel-zinc alloys without silver as their defining element. The cast system has corresponding families plus ranges for leaded coppers and special alloys. Family names are helpful for navigation, but they are not a substitute for checking composition.

What the number does not establish

The Copper Development Association explicitly cautions that a UNS designation is not a specification. A designation does not, by itself, verify a supplied heat, chemistry test, temper, product dimensions, strength, hardness, conductivity, corrosion performance or acceptance criteria. Those requirements come from the applicable material specification, purchase order, certification and drawing. Even two materials within a family can differ significantly in properties and intended use.

Before releasing a design or purchase, record the full alloy designation, product form and temper. Then check the applicable ASTM, SAE, EN or other contractually required specification and confirm the supplier certificate matches it. Where properties matter, use values for the exact alloy, product form, condition, thickness or diameter, and test direction. Do not infer a property from a UNS range or a familiar family name.

Practical lookup sequence

Start with the product form shown on the material certificate. Determine whether it is wrought or cast, then use the matching half of the table to locate the family range. Find the exact UNS number in a current alloy register or the product supplier’s technical data. Finally, verify the grade-specific specification and condition required by the application. If the alloy lies outside the listed family range or the certificate uses another designation system, ask the supplier for a documented cross-reference rather than guessing from a similar number.

This table follows the Copper Development Association’s 2025 designation chart. The CDA describes these designations as a means of identifying alloys, not as a replacement for the controlling specification. Use it as an index to the next source in your material-selection process, not as a stand-alone engineering approval.

One further check is the revision date. CDA maintains an active alloy list, and designations can be added, changed or marked inactive. A printed family chart may be useful for orientation, but a current alloy register and the purchase specification control the material decision. If two systems use similar names, compare the registered designation and specification number rather than matching the names alone.