Machinability of Metals


Machinability is the defined as the ease with which a material can be machined. The American Iron and Steel Institute has determined that AISI 1112 Steel has a machinability of 100%. Other materials are compared below:

Carbon Steels

  • 1015 – 72%
  • 1018 – 78%
  • 1020 – 72%
  • 1022 – 78%
  • 1030 – 70%
  • 1040 – 64%
  • 1042 – 64%
  • 1050 – 54%
  • 1095 – 42%
  • 1117 – 91%
  • 1137 – 72%
  • 1141 – 70%
  • 1141 annealed – 81%
  • 1144 – 76%
  • 1144 annealed – 85%
  • 1144 stress-proof – 83%
  • 1212 – 100%
  • 1213 – 136%
  • 12L14 – 170%
  • 1215 – 136%

Alloy Steels

  • 2355 annealed – 70%
  • 4130 annealed – 72%
  • 4140 annealed – 66%
  • 4142 annealed – 66%
  • 41L42 annealed – 77%
  • 4150 annealed – 60%
  • 4340 annealed – 57%
  • 4620 – 66%
  • 4820 annealed – 49%
  • 52100 annealed – 40%
  • 6150 annealed – 60%
  • 8620 – 66%
  • 86L20 – 77%
  • 9310 annealed – 51%

Stainless Steels and Super Alloys

  • 302 annealed – 45%
  • 303 annealed – 78%
  • 304 annealed – 45%
  • 316 annealed – 45%
  • 321 annealed – 36%
  • 347 annealed – 36%
  • 410 annealed – 54%
  • 416 annealed – 110%
  • 420 annealed – 45%
  • 430 annealed – 54%
  • 431 annealed – 45%
  • 440A – 45%
  • 15-5PH condition A – 48%
  • 17-4PH condition A – 48%
  • A286 aged – 33%
  • Hastelloy X – 19%

Tool Steels

  • A-2 – 42%
  • A-6 – 33%
  • D-2 – 27%
  • D-3 – 27%
  • M-2 – 39%
  • O-1 – 42%
  • O-2 – 42%

Gray Cast Iron

  • ASTM class 20 annealed – 73%
  • ASTM class 25 – 55%
  • ASTM class 30 – 48%
  • ASTM class 35 – 48%
  • ASTM class 40 – 48%
  • ASTM class 45 – 36%
  • ASTM class 50 – 36%

Nodular Ductile Iron

  • 60-40-18 annealed – 61%
  • 65-45-12 annealed – 61%
  • 80-55-06 – 39%

Aluminum / Magnesium Alloys

  • aluminum, cold drawn – 360%
  • aluminum, cast – 450%
  • aluminum, die cast – 76%
  • magnesium, cold drawn – 480%
  • magnesium, cast – 480%

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