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Unified Numbering System

Alloy numbering systems vary greatly from one alloy group to the next. To help alleviate this problem the Unified Numbering System (UNS) for metals and alloys was developed. An outline of the organization of UNS designations is listed below:

UNS Series


A00001 to A99999

Aluminum and aluminum alloys

C00001 to C99999

Copper and copper alloys

D00001 to D99999

Specified mechanical property steels

E00001 to E99999

Rare earth and rare earthlike metals and alloys

F00001 to F99999

Cast irons

G00001 to G99999

AISI and SAE carbon and alloy steels (except tool steels)

H00001 to H99999

AISI and SAE H-steels

J00001 to J99999

Cast steels (except tool steels)

K00001 to K99999

Miscellaneous steels and ferrous alloys

L00001 to L99999

Low-melting metals and alloys

M00001 to M99999

Miscellaneous nonferrous metals and alloys

N00001 to N99999

Nickel and nickel alloys

P00001 to P99999

Precious metals and alloys

R00001 to R99999

Reactive and refractory metals and alloys

S00001 to S99999

Heat and corrosion resistant (stainless) steels

T00001 to T99999

Tool steels, wrought and cast

W00001 to W99999

Welding filler metals

Z00001 to Z99999

Zinc and zinc alloys