ISO group Subgroup WMG (Work Material Group) kvG Examples of material (AISI, EN, DIN, ČSN, GB, SS, STN, BS, UNE, AFNOR, ASTM, GOST, UNS, UNI, ...) Free machining sulfurized carbon steel with a AISI 1108, EN 15S22, DIN 1.0723, SS 1922, ČSN 11120, BS 210A15, UNE F.210F, GB Y15, AFNOR 10F1, P1.1 1.33 hardness of < 220 HB GOST A30, UNI CF10S20​ Free machining steel Free machining sulfurized and phosphorized AISI 1211, EN 11SMn30, DIN 1.0715, SS 1912, ČSN 11109, BS 230M7, UNE F.2111, GB Y15, AFNOR S250, P1 P1.2 1.49 (carbon steels with increased machinability) carbon steel with a hardness of < 180 HB GOST A40G, UNI CF9SMn28​ Free machining sulfurized/phosphorized AISI 12L13, EN 11SMnPb30, DIN 1.0718, SS 1914, ČSN 12110, BS 210M16, UNE F.2114, GB Y15Pb, P1.3 and leaded carbon steel with a hardness 1.53 AFNOR S250Pb, GOST AS35G2, UNI CF10SPb20​ of < 160 HB Plain low carbon steel containing < 0.25 % C AISI 1015, EN C15, DIN 1.0401, SS 1350, ČSN 11301 , BS 080A15, UNE F.111, GB 15, AFNOR C18RR, P2.1 1.14 with a hardness of < 180 HB GOST St2ps, UNI Fe360​ Plain carbon steel Plain medium carbon steel containing AISI 1030, EN C30, DIN 1.0528, SS 1550, ČSN 12031, BS 080M32, UNE F.1130, GB 30, AFNOR AF50C30, P2 P2.2 1.00 (steels comprised of mainly iron and carbon) < 0.55 %C with a hardness of < 240 HB GOST 30G, UNI Fe590​ Plain high carbon steel containing > 0.55 % C, AISI 1060, EN C60, DIN 1.0601, SS 1655, ČSN 12061, BS 080A62, UNE F513, GB 60, AFNOR 1C60, 9 Steel and cast steel P2.3 0.89 with a hardness of < 300 HB GOST 60G, UNI C60​ (steels with alloy P content ≤ 10 % and a hardness of < 45HRC) AISI 5015, EN 16Mo3, DIN 1.5415, SS 2912, ČSN 15020, BS 1501-240, UNE F.2601, GB 16Mo, P3.1 Alloy steel with a hardness of < 180 HB 0.92 AFNOR 15D3, GOST 15M, UNI 16Mo3KW​ Alloy steel AISI 4140, EN 42CrMo4, DIN 1.7225, SS 2244, ČSN 15142, BS 708M40, UNE F.8232, GB 42CrMo, P3 (carbon steels with an alloying content P3.2 Alloy steel with a hardness of 180 – 260 HB 0.74 AFNOR 42CD4, GOST 40ChFA, UNI 42CrMo4​ ≤ 10 %) AISI 4140, EN 42CrMo4, DIN 1.7225, SS 2244, ČSN 15142, BS 708M40, UNE F.8232, GB 42CrMo, P3.3 Alloy steel with a hardness of 260 – 360 HB 0.63 AFNOR 42CD4, GOST 40ChFA, UNI 42CrMo4​ AISI D2, EN X155CrVMo12-1, DIN 1.2370, SS 2736, ČSN 19573, BS BD2, UNE F.520A, GB Cr12Mo1V1, P4.1 Tool steel with a hardness of < 26 HRC 0.55 AFNOR Z160CDV12, GOST Ch12MF, UNI X155CrVMo121KU​ Tool steel AISI D2, EN X155CrVMo12-1, DIN 1.2370, SS 2736, ČSN 19573, BS BD2, UNE F.520A, GB Cr12Mo1V1, P4 P4.2 Tool steel with a hardness of 26 – 39 HRC 0.47 (special alloy steel for tools, dies and molds) AFNOR Z160CDV12, GOST Ch12MF, UNI X155CrVMo121KU​ AISI D2, EN X155CrVMo12-1, DIN 1.2370, SS 2736, ČSN 19573, BS BD2, UNE F.520A, GB Cr12Mo1V1, P4.3 Tool steel with a hardness of 39 – 45 HRC 0.38 AFNOR Z160CDV12, GOST Ch12MF, UNI X155CrVMo121KU​ WORKPIECE MATERIAL GROUP (WMG) 693