9 WMG (WORK MATERIAL GROUP) WMG (Work Material Group) ISO group P1 P P2 P3 P4 M1 M2 M M3 M4 K1 K2 K3 K K4 K5 N1 N2 N N3 P1.1 P1.2 P1.3 P2.1 P2.2 P2.3 P3.1 P3.2 P3.3 P4.1 P4.2 P4.3 M1.1 M1.2 M2.1 M2.2 M2.3 M3.1 M3.2 M3.3 Free machining steel (carbon steels with increased machinability) Plain carbon steel (steels comprised of mainly iron and carbon) Alloy steel (carbon steels with an alloying content ≤ 10%) Tool steel (special alloy steel for tools, dies and molds) N5 S1 S S2 S3 S4 H1 H H2 H3 H4 Hardened and tempered Annealed Hardened and tempered Ferritic stainless steel (straight chromium non-hardenable alloys) Martensitic stainless steel (straight chromium hardenable alloys) Annealed Quenched and tempered Precipitation-hardened Austenitic stainless steel (chromium-nickel and chromium-nickel-manganese alloys) M4.1 Austenitic-ferritic (DUPLEX) or super-austenitic stainless steel M4.2 Precipitation hardening austenitic stainless steel K1.1 K1.2 K1.3 K2.1 K2.2 K2.3 K3.1 K3.2 K3.3 Gray iron or Automotive Gray iron (GG) (iron-carbon castings with a lamellar graphite microstructure) Malleable iron (GTS/GTW) (iron-carbon castings with a graphite-free microstructure) Ductile iron (GGG) (iron-carbon castings with a nodular graphite microstructure) Ferritic or ferritic-pearlitic Ferritic-pearlictic or pearlitic Pearlitic Ferritic Ferritic or pearlitic Pearlitic Ferritic Ferritic or pearlitic Pearlitic Ultimate Tensile Strength (MPa) < 240 HB < 180 HB < 180 HB < 180 HB < 240 HB < 300 HB < 180 HB 180 – 260 HB 260 – 360 HB < 26 HRC 26 – 39 HRC 39 – 45 HRC < 160 HB 160 – 220 HB < 200 HB 200 – 280 HB 280 – 380 HB < 200 HB 200 – 260 HB 260 – 300 HB ≤ 830 ≤ 620 ≤ 620 ≤ 620 ≤ 830 ≤ 1030 ≤ 620 > 620 ≤ 900 > 900 ≤ 1240 ≤ 900 > 900 ≤ 1240 > 1240 ≤ 1450 ≤ 520 > 520 ≤ 700 ≤ 670 > 670 ≤ 950 > 950 ≤ 1300 ≤ 750 > 750 ≤ 870 > 870 ≤ 1040 < 300 HB ≤ 990 300 – 380 HB ≤ 1320 < 180 HB 180 – 240 HB 240 – 280 HB < 160 HB 160 – 200 HB 200 – 240 HB < 180 HB 180 – 220 HB 220 – 260 HB ≤ 190 > 190 ≤ 310 > 310 ≤ 390 ≤ 400 > 400 ≤ 550 > 550 ≤ 660 ≤ 560 > 560 ≤ 680 > 680 ≤ 800 K4.1 Austenitic gray iron (ASTM A436) (iron-carbon alloy castings with an austenitic lamellar graphite microstructure) < 180 HB ≤ 190 K4.2 Austenitic ductile iron (ASTM A439 or ASTM A571) (iron-carbon alloy castings with an austenitic nodular graphite microstructure) < 240 HB ≤ 740 < 280 HB 280 – 320 HB 320 – 360 HB < 180 HB 180 – 220 HB 220 – 260 HB < 60 HB 60 – 100 HB 100 – 150 HB < 75 HB 75 – 90 HB 90 – 140 HB > 840 ≤ 980 > 980 ≤ 1130 > 1130 ≤ 1280 ≤ 400 > 400 ≤ 450 > 450 ≤ 500 ≤ 240 > 240 ≤ 400 > 400 ≤ 590 ≤ 240 > 240 ≤ 270 > 270 ≤ 440 N3.1 Free-cutting copper-alloys materials with excellent machining properties – – N3.2 Short-chip copper-alloys with good to moderate machining properties – – K4.3 K4.4 K4.5 K5.1 K5.2 K5.3 N1.1 N1.2 N1.3 N2.1 N2.2 N2.3 Austempered ductile iron (ASTM A897) (iron-carbon alloy castings with an ausferrite microstructure) Compacted graphite iron CGI (ASTM A842) (iron-carbon castings with a vermicular graphite structure) N4.1 N4.2 N4.3 N5.1 S1.1 S1.2 S1.3 S2.1 S2.2 S3.1 S3.2 S4.1 S4.2 H1.1 H2.1 H2.2 H3.1 H3.2 H4.1 H4.2 Ferritic Ferritic-pearlitic Pearlitic Commercially pure wrought aluminium Wrought aluminium alloys Cast aluminium alloys N3.3 Electrolytic copper and long-chip copper-alloys with moderate to poor machining properties N4 Sulfurized Sulfurized and phosphorized Sulfurized/phosphorized and leaded Containing <0.25 % C Containing <0.55 % C Containing >0.55 % C Annealed Hardness (HB or HRC) Thermoplastic polymers Thermosetting polymers Reinforced polymers or composites Graphite Titanium or titanium alloys Fe-based high-temperature alloys Ni-based high-temperature alloys Co-based high-temperature alloys Chilled cast iron Hardened cast iron Hardened steel <55 HRC Hardened steel >55 HRC Half hard tempered Full hard tempered – – – – – – < 200 HB 200 – 280 HB 280 – 360 HB < 200 HB 200 – 280 HB < 280 HB 280 – 360 HB < 240 HB 240 – 320 HB < 440 HB < 55 HRC > 55 HRC < 51 HRC 51 – 55 HRC 55 – 59 HRC > 59 HRC – – – – ≤ 660 > 660 ≤ 950 > 950 ≤ 1200 ≤ 690 > 690 ≤ 970 ≤ 940 > 940 ≤ 1200 ≤ 800 > 800 ≤ 1070 – – – – – – – 7