Introduction to the Unified Numbering System of Nonferrous Metals and Alloys

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Unified numbering system (UNS) is a system of designations established in accordance with ASTM E527 and SAE J1086, Recommended Practice for Numbering Metals and Alloys. Its purpose is to provide means of correlating systems in use by such organizations as American Society for Testing Materials (ASTM) and Aluminum Association (AA), as well as individual users and producers.

UNS designation assignments are processed the ASTM, or other relevant trade associations. Each of these assignors has the responsibility for administering a specific UNS series of designations. Each considers requests for the assignment of new UNS designations, and informs the applicants of the action taken. UNS designation assignors report immediately to the office of the Unified Numbering System for Metals and Alloys the details of each new assignment for inclusion into the system.

The UNS number is not in itself a specification, since it establishes no requirements for form, condition, quality, etc. It is a unified identification of metals and alloys for which controlling limits have been established in specifications published elsewhere.

This designation system establishes 9 series of designations for nonferrous metals and alloys. Each UNS designation consists of a single-letter prefix followed by five digits. In most cases the letter is suggestive of the family of metals identified: for example, A - for aluminum, C - Copper and Copper Alloys, Z - Zinc and Zinc Alloys, etc.

The UNS provides a means of correlating many internationally used numbering systems currently administered by societies, trade associations, and individual users and producers of metals and alloys, thereby avoiding confusion caused by use of more than one identification number for the same material and by the opposite situation of having the same number assigned to two or more entirely different materials. It provides, also, the uniformity necessary for efficient indexing, record keeping, data storage and retrieval, and cross referencing.

Table1. Description of Numbers (or Codes) Established for Nonferrous Metals and Alloys

A00001-A99999	Aluminum and aluminum alloys
A01001-A63562	Aluminum Foundry Alloys, Ingot or Casting
A82014-A87475	Wrought Aluminum Alloys Clad with Wrought Aluminum Alloys, Non- or Heat Treatable
A91030- A91450	Wrought Aluminum Alloys, Non- Heat Treatable
A93002-A95954	Wrought Aluminum Alloys, Non- Heat Treatable
A98001-A98280	Wrought Aluminum Alloys, Non- Heat Treatable
A92001-A92618	Wrought Aluminum Alloys, Heat Treatable
A96002-A97472	Wrought Aluminum Alloys, Heat Treatable
C00001-C99999	Copper and copper alloys
Wrought Alloys
C10100-C15760	Pure and Low Alloyed Copper (>99%Cu)
C16200-C16500	Cadmium Copper
C17000-C17700	Copper-Beryllium Alloy (Beryllium Bronzes)
C18000-C19900	Copper and High Copper Alloys (>96%Cu)
C20500-C29800	Brasses (Cu-Zn)
C31000-C35600	Leaded Brasses (Cu-Zn-Pb )
C40400-C49080	Tin Brasses (Cu-Zn-Sn-Pb)
C50100-C52900	Phosphor bronzes (Cu-Sn-P)
C53200-C54800	Leaded Phosphor Bronzes
C55180-C56000	Cu-Ag-P and Cu-P Brazing Filler Metal
C60600-C64400	Aluminum Bronzes
C64700-C66100	Silicon Bronzes
C66200-C66420	Copper Alloys
C66700-C67820	Manganese Bronzes
C68000-C69950	Silicon Brasses and Other Copper-Zinc Alloys
C70100-C72950	Copper-Nickel Alloys
C73150-C79900	Nickel Silvers and Leaded Nickel Silvers
Cast alloys
C80100-C81200	Cast Coppers (>99%Cu)
C81300-C82800	Cast Chromium Copper and Beryllium Copper Alloys (>96%Cu)
C83300-C85800	Cast Red, Yellow and Leaded Brasses
C86100-C86800	Cast Manganese Bronzes and Leaded Manganese Bronzes
C87300-C87900	Cast Silicon Brasses and Bronzes
C89320-C89940	Cast Cu-Sn-Bi-(Se, Zn, Ni) Alloys
C90200-C94500	Tin Bronzes and Leaded Tin Bronzes
C94700-C94900	Cast Nickel-Tin Bronzes
C95200-C95810	Cast Aluminum Bronzes
C96200-C96800	Cast Copper-Nickel Alloys
C97300-C97800	Cast Nickel-Silver Alloys
C98200-C98840	Cast Leaded Copper Alloys
C99300-C99750	Cast Copper Alloys
E00001-E99999	Rare earth and rare earth-like metals and alloys
E00000-E00999	Actinium
EO1000-E20999	Cerium
E21000-E45999	Mixed rare earths
E46000-E47999	Dysprosium
E48000-E49999	Erbium
E50000-E51999	Europium
E52000-E55999	Gadolinium
E56000-E57999	Holmium
E58000-E67999	Lanthanum
E68000-E68999	Lutetium
E69000-E73999	Neodymium
E74000-E77999	Praseodymium
E78000-E78999	Promethium
E79000-E82999	Samarium
E83000-E84999	Scandium
E85000-E86999	Terbium
E87000-E87999	Thulium
E88000-E89999	Ytterbium
E90000-E99999	Yttrium
L00001-L99999	Low-melting metals and alloys
L00001-L00999	Bismuth
L01001-L01999	Cadmium
L02001-L02999	Cesium
L03001-L03999	Gallium
L04001-L04999	Indium
L06001-L06999	Lithium
L07001-L07999	Mercury
L08001-L08999	Potassium
L09001-L09999	Rubidium
L10001-L10999	Selenium
L11001-L11999	Sodium
L13001-L13999	Tin
L50001-L59999	Lead
M00001-M99999	Miscellaneous nonferrous metals and alloys
M00001-M00999	Antimony
M01001-M01999	Arsenic
M02001-M02999	Barium
M03001-M03999	Calcium
M04001-M04999	Germanium
M05001-M05999	Plutonium
M06001-M06999	Strontium
M07001-M07999	Tellurium
M08001-M08999	Uranium
M10001-M19999	Magnesium
M20001-M29999	Manganese
M30001-M39999	Silicon
P00001-P99999	Precious metals and alloys
P00001-P00999	Gold
P01001-P01999	Iridium
P02001-P02999	Osmium
P03001-P03999	Palladium
P04001-P04999	Platinum
P05001-P05999	Rhodium
P06001-P06999	Ruthenium
P07001-P07999	Silver
R00001-R99999	Reactive and refractory metals and alloys
R01001-R01999	Boron
R02001.R02999	Hafnium
R03001-R03999	Molybdenum
R04001.R04999	Niobium (Columbium)
R05001-R05999	Tantalum
R06001-R06999	Thorium
R07001.R07999	Tungsten
R08001-R08999	Vanadium
R10001.R19999	Beryllium
R20001-R29999	Chromium
R30001.R39999	Cobalt
R40001.R49999	Rhenium
R50001-R59999	Titanium
R60001-R69999	Zirconium
W00001-W99999	Welding filler metals, classified by weld deposit composition
W60000-W69999	Copper base alloys
W70000-W79999	Surfacing alloys
W80000-W89999	Nickel base alloys
Z00001-Z99999	Zinc and zinc alloys