Unified Numbering System

Unified Numbering System (UNS)

The Unified Numbering System is a coding system consisting of a letter, followed by five digits to categorize metal and alloy for commercial usage. This system was developed in 1974 by the American National Standards Institute (ANSI) and intended to be a set standard across North America. Unfortunately the Unified Numbering System does not dictate the composition or performance specification of a material.

Unified Numbering System (UNS) for Metals & Alloys
UNS Series Material
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 earth like 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

Copper & Copper Alloys

UNS Numbers Materials
C10000 to C19999 Coppers, high-copper alloys
C20000 to C29999 Brasses
C30000 to C39999 Brasses
C40000 C49999 Brasses
C66400 to C69800 Brasses
C50000 to C59999 Phosphor bronzes
C60600 to C64200 Aluminum bronzes
C64700 to C66100 Silicon bronzes
C70000 to C79999 Copper nickels, nickel silvers

Plain Carbon Steels (AISI-SAE to UNS)

AISI-SAE Numbers UNS Numbers AISI-SAE Numbers UNS Numbers
1005 G10050 1070 G10700
1006 G10060 1078 G10780
1008 G10080 1080 G10800
1010 G10100 1084 G10840
1012 G10120 1086 G10860
1015 G10150 1090 G10900
1016 G10160 1095 G10950
1017 G10170 1513 G15130
1018 G10180 1522 G15220
1019 G10190 1524 G15240
1020 G10200 1526 G15260
1021 G10210 1527 G15270
1022 G10220 1541 G15410
1023 G10230 1548 G15480
1025 G10250 1551 G15510
1026 G10260 1552 G15520
1029 G10290 1561 G15610
1030 G10300 1566 G15660
1035 G10350 1110 G11100
1037 G10370 1117 G11170
1038 G10380 1118 G11180
1039 G10390 1137 G11370
1040 G10400 1139 G11390
1042 G10420 1140 G11400
1043 G10430 1141 G11410
1044 G10440 1144 G11440
1045 G10450 1146 G11460
1046 G10460 1151 G11510
1049 G10490 1211 G12110
1050 G10500 1212 G12120
1053 G10530 1213 G12130
1055 G10550 1215 G12150
1059 G10590 12L14 G12144
1060 G10600 -- --

Alloy Steels (AISI-SAE to UNS)

AISI-SAE Numbers UNS Numbers AISI-SAE Numbers UNS Numbers
1330 G13300 5135 G51350
1335 G13350 5140 G51400
1340 G13400 5150 G51500
1345 G13450 5155 G51550
4023 G40230 5160 G51600
4024 G40240 E51100 G51986
4027 G40270 E52100 G52986
4028 G40280 6118 G61180
4037 G40370 6150 G61500
4047 G40470 8615 G86150
4118 G41180 8617 G86170
4130 G41300 8620 G86200
4137 G41370 8622 G86220
4140 G41400 8625 G86250
4142 G41420 8627 G86270
4145 G41450 8630 G86300
4147 G41470 8637 G86370
4150 G41500 8640 G86400
4161 G41610 8642 G86420
4320 G43200 8645 G86450
4340 G43400 8655 G86550
E4340 G43406 8720 G87200
4615 G46150 8740 G87400
4620 G46200 8822 G88220
4626 G46260 9260 G92600
4720 G47200 50B44 G50441
4815 G48150 50B46 G50461
4817 G48170 50B50 G50501
4820 G48200 50B60 G50601
5117 G51170 51B60 G51601
5120 G51200 81B45 G81451
5130 G51300 94B17 G94171
5132 G51320 94B30 G94301

Tool Steels (AISI to UNS)

AISI Numbers UNS Numbers AISI Numbers UNS Numbers
M1 T11301 A5 T30105
M2 T11302 A6 T30106
M4 T11304 A7 T30107
M6 T11306 A8 T30108
M7 T11307 A9 T30109
M10 T11310 A10 T30110
M3-1 T11313 D2 T30402
M3-2 T11323 D3 T30403
M30 T11330 D4 T30404
M33 T11333 D5 T30405
M34 T11334 D7 T30407
M36 T11336 O1 T31501
M41 T11341 O2 T31502
M42 T11342 O6 T31506
M43 T11343 O7 T31507
M44 T11344 S1 T41901
M46 T11346 S2 T41902
M47 T11347 S4 T41904
T1 T12001 S5 T41905
T2 T12002 S6 T41906
T4 T12004 S7 T41907
T5 T12005 P2 T51602
T6 T12006 P3 T51603
T8 T12008 P4 T51604
T15 T12015 P5 T51605
H10 T20810 P6 T51606
H11 T20811 P20 T51620
H12 T20812 P21 T51621
H13 T20813 F1 T60601
H14 T20814 F2 T60602
H19 T20819 L2 T61202
H21 T20821 L3 T61203
H22 T20822 L6 T61206
H23 T20823 W1 T72301
H24 T20824 W2 T72302
H25 T20825 W5 T72305
H26 T20826 CA2 T90102
H41 T20841 CD2 T90402
H42 T20842 CD5 T90405
H43 T20843 CH12 T90812
A2 T30102 CH13 T90813
A3 T30103 CO1 T91501
A4 T30104 CS5 T91905