Steel - Aluminum - Magnesium - Machinability Index Chart
Metals and Materials Table of Content
The following is a simplified general Steel - Aluminum - Magnesium - Machinability Index Chart. Carbon steel 1212 is the universal reference (1212 = 100%)
Carbon steels: |
Index Percent Relative to 1212 Carbon Steel |
1212 |
100% |
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% |
1213 |
136% |
12L14 |
170% |
1215 |
136% |
Alloy steels: |
Index Percent Relative to 1212 Carbon Steel |
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: |
Index Percent Relative to 1212 Carbon Steel |
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 |
48% |
17-4PH |
48% |
A286 aged |
33% |
Hastelloy X |
19% |
Tool Steels: |
Index Percent Relative to 1212 Carbon Steel |
A-2 |
42% |
A-6 |
33% |
D-2 |
27% |
D-3 |
27% |
M-2 |
39% |
O-1 |
42% |
O-2 |
42% |
Gray Cast Iron: |
Index Percent Relative to 1212 Carbon Steel |
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% |
Aluminum and Magnesium Alloys: |
Index Percent Relative to 1212 Carbon Steel |
aluminum, cold drawn |
360% |
aluminum, cast |
450% |
aluminum, die cast |
76% |
magnesium, cold drawn |
480% |
magnesium, cast |
480% |