Tool Steel Heat Treatment Data
Normalizing, Annealing, Hardening & Tempering of Tool Steels
Complete reference for heat-treating temperatures of all major tool steel grades. Search by grade name, toggle between °C and °F, and expand each category group for full specification data. The quench and temper schedule is also published as a standalone table in the hardening and tempering temperature chart, and the overall process sequence is covered in the tool steel heat treatment guide.
O = Oil quench A = Air cool S = Salt bath quench W = Water quench B = Brine quench
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Molybdenum High-Speed Steels 9 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| M1, M10 | Do not normalize | 815-870 | 1500-1600 | 22 | 40 | 207-235 |
| M2 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 212-241 |
| M3, M4 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 223-255 |
| M7 | Do not normalize | 815-870 | 1500-1600 | 22 | 40 | 217-255 |
| M30, M33, M34, M35, M36, M41, M42, M46, M47 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 235-269 |
| M43 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 248-269 |
| M44 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 248-293 |
| M48 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 285-311 |
| M62 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 262-285 |
Tungsten High-Speed Steels 7 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| T1 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 217-255 |
| T2 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 223-255 |
| T4 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 229-269 |
| T5 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 235-277 |
| T6 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 248-293 |
| T8 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 229-255 |
| T15 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 241-277 |
Intermediate High-Speed Steels 2 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| M50 | Do not normalize | 830-845 | 1525-1550 | 22 | 40 | 197-235 |
| M52 | Do not normalize | 830-845 | 1525-1550 | 22 | 40 | 197-235 |
Chromium Hot-Work Steels 3 grades ▾
Tungsten Hot-Work Steels 3 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| H21, H22, H25 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 207-235 |
| H23 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 212-255 |
| H24, H26 | Do not normalize | 870-900 | 1600-1650 | 22 | 40 | 217-241 |
Molybdenum Hot-Work Steels 2 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| H41, H43 | Do not normalize | 815-870 | 1500-1600 | 22 | 40 | 207-235 |
| H42 | Do not normalize | 845-900 | 1550-1650 | 22 | 40 | 207-235 |
High-Carbon, High-Chromium Cold-Work Steels 3 grades ▾
Medium-Alloy, Air-Hardening Cold-Work Steels 8 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| A2 | Do not normalize | 845-870 | 1550-1600 | 22 | 40 | 201-229 |
| A3 | Do not normalize | 845-870 | 1550-1600 | 22 | 40 | 207-229 |
| A4 | Do not normalize | 740-760 | 1360-1400 | 14 | 25 | 200-241 |
| A6 | Do not normalize | 730-745 | 1350-1375 | 14 | 25 | 217-248 |
| A7 | Do not normalize | 870-900 | 1600-1650 | 14 | 25 | 235-262 |
| A8 | Do not normalize | 845-870 | 1550-1600 | 22 | 40 | 192-223 |
| A9 | Do not normalize | 845-870 | 1550-1600 | 14 | 25 | 212-248 |
| A10 | 790 / 1450 | 765-795 | 1410-1460 | 8 | 15 | 235-269 |
Oil-Hardening Cold-Work Steels 4 grades ▾
Shock-Resisting Steels 4 grades ▾
Mold Steels 7 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| P2 | Not required | 730-815 | 1350-1500 | 22 | 40 | 103-123 |
| P3 | Not required | 730-815 | 1350-1500 | 22 | 40 | 109-137 |
| P4 | Do not normalize | 870-900 | 1600-1650 | 14 | 25 | 116-128 |
| P5 | Not required | 845-870 | 1550-1600 | 22 | 40 | 105-116 |
| P6 | Not required | 845 | 1550 | 8 | 15 | 183-217 |
| P20 | 900 / 1650 | 760-790 | 1400-1450 | 22 | 40 | 149-179 |
| P21 | 900 / 1650 | Do not anneal | Do not anneal | — | — | — |
Low-Alloy Special-Purpose Steels 3 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| L2 | 871-900 / 1600-1650 | 760-790 | 1400-1450 | 22 | 40 | 163-197 |
| L3 | 900 / 1650 | 790-815 | 1450-1500 | 22 | 40 | 174-201 |
| L6 | 870 / 1600 | 760-790 | 1400-1450 | 22 | 40 | 183-212 |
Carbon-Tungsten Special-Purpose Steels 2 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| F1 | 900 / 1650 | 760-800 | 1400-1475 | 22 | 40 | 183-207 |
| F2 | 900 / 1650 | 790-815 | 1450-1500 | 22 | 40 | 207-235 |
Water-Hardening Steels 2 grades ▾
| Type | Normalizing (a) | Annealing °C | Annealing °F | Cooling max °C/h | Cooling max °F/h | Hardness, HB |
|---|---|---|---|---|---|---|
| W1, W2 | 790-925 (d) | 740-790 (e) | 1360-1450 (e) | 22 | 40 | 156-201 |
| W5 | 870-925 / 1600-1700 | 760-790 | 1400-1450 | 22 | 40 | 163-201 |
Notes & References
- (a) Time held at temperature varies from 15 min for small sections to 1 h for large sizes. Cooling is done in still air. Normalizing should not be confused with low-temperature annealing.
- (b) The upper limit of ranges should be used for large sections, and the lower limit for smaller sections. Time held at temperature varies from 1 h for light sections to 4 h for heavy sections and large furnace charges of high-alloy steel.
- (c) For 0.25 Si type, 183 to 207 HB; for 1.00 Si type, 207 to 229 HB.
- (d) Temperature varies with carbon content: 0.60–0.75 C, 815 °C (1500 °F); 0.75–0.90 C, 790 °C (1450 °F); 0.90–1.10 C, 870 °C (1600 °F); 1.10–1.40 C, 870–925 °C (1600–1700 °F).
- (e) Temperature varies with carbon content: 0.60–0.90 C, 740–790 °C (1360–1450 °F); 0.90–1.40 C, 760–790 °C (1400–1450 °F).
Molybdenum High-Speed Steels 12 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| M1, M7, M10 | Rapidly from preheat | 730-845 | 1350-1550 | 1175-1220 (b) | 2150-2225 (b) | 2-5 | O, A, or S | 540-595 (c) | 1000-1100 (c) |
| M2 | Rapidly from preheat | 730-845 | 1350-1550 | 1190-1230 (b) | 2175-2250 (b) | 2-5 | O, A, or S | 540-595 (c) | 1000-1100 (c) |
| M3, M4, M30, M33, M34, M35 | Rapidly from preheat | 730-845 | 1350-1550 | 1205-1230 (b) | 2200-2250 (b) | 2-5 | O, A, or S | 540-595 (c) | 1000-1100 (c) |
| M36 | Rapidly from preheat | 730-845 | 1350-1550 | 1220-1245 (b) | 2225-2275 (b) | 2-5 | O, A, or S | 540-595 (c) | 1000-1100 (c) |
| M41 | Rapidly from preheat | 730-845 | 1350-1550 | 1190-1215 (b) | 2175-2220 (b) | 2-5 | O, A, or S | 540-595 (d) | 1000-1100 (d) |
| M42 | Rapidly from preheat | 730-845 | 1350-1550 | 1190-1210 (b) | 2175-2210 (b) | 2-5 | O, A, or S | 510-595 (d) | 950-1100 (d) |
| M43 | Rapidly from preheat | 730-845 | 1350-1550 | 1190-1215 (b) | 2175-2220 (b) | 2-5 | O, A, or S | 510-595 (d) | 950-1100 (d) |
| M44 | Rapidly from preheat | 730-845 | 1350-1550 | 1200-1225 (b) | 2190-2240 (b) | 2-5 | O, A, or S | 540-625 (d) | 1000-1160 (d) |
| M46 | Rapidly from preheat | 730-845 | 1350-1550 | 1190-1220 (b) | 2175-2225 (b) | 2-5 | O, A, or S | 525-565 (d) | 975-1050 (d) |
| M47 | Rapidly from preheat | 730-845 | 1350-1550 | 1175-1200 (b) | 2150-2200 (b) | 2-5 | O, A, or S | 525-595 (d) | 975-1100 (d) |
| M48 | Rapidly from preheat | 730-845 | 1350-1550 | 1175-1200 (b) | 2150-2200 (b) | 2-5 | O, A, or S | 540-595 (d) | 1000-1100 (d) |
| M62 | Rapidly from preheat | 730-845 | 1350-1550 | 1175-1200 (b) | 2150-2200 (b) | 2-5 | O, A, or S | 540-595 (d) | 1000-1100 (d) |
Tungsten High-Speed Steels 3 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| T1, T2, T4, T8 | Rapidly from preheat | 815-870 | 1500-1600 | 1260-1300 (b) | 2300-2375 (b) | 2-5 | O, A, or S | 540-595 (c) | 1000-1100 (c) |
| T5, T6 | Rapidly from preheat | 815-870 | 1500-1600 | 1275-1300 (b) | 2325-2375 (b) | 2-5 | O, A, or S | 540-595 (c) | 1000-1100 (c) |
| T15 | Rapidly from preheat | 815-870 | 1500-1600 | 1205-1260 (b) | 2200-2300 (b) | 2-5 | O, A, or S | 540-650 (d) | 1000-1200 (d) |
Intermediate High-Speed Steels 2 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| M50 | Rapidly from preheat | 730-845 | 1350-1550 | 1095-1120 | 2000-2050 | 2-5 | O, A, or S | 525-595 | 975-1100 |
| M52 | Rapidly from preheat | 730-845 | 1350-1550 | 1120-1175 | 2050-2150 | 2-5 | O, A, or S | 525-595 | 975-1100 |
Chromium Hot-Work Steels 5 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| H10 | Moderately from preheat | 815 | 1500 | 1010-1040 | 1850-1900 | 15-40 (e) | A | 540-650 | 1000-1200 |
| H11, H12 | Moderately from preheat | 815 | 1500 | 995-1025 | 1825-1875 | 15-40 (e) | A | 540-650 | 1000-1200 |
| H13 | Moderately from preheat | 815 | 1500 | 995-1040 | 1825-1900 | 15-40 (e) | A | 540-650 | 1000-1200 |
| H14 | Moderately from preheat | 815 | 1500 | 1010-1065 | 1850-1950 | 15-40 (e) | A | 540-650 | 1000-1200 |
| H19 | Moderately from preheat | 815 | 1500 | 1095-1205 | 2000-2200 | 2-5 | A or O | 540-705 | 1000-1300 |
Tungsten Hot-Work Steels 5 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| H21, H22 | Rapidly from preheat | 815 | 1500 | 1095-1205 | 2000-2200 | 2-5 | A or O | 595-675 | 1100-1250 |
| H23 | Rapidly from preheat | 845 | 1550 | 1205-1260 | 2200-2300 | 2-5 | O | 650-815 | 1200-1500 |
| H24 | Rapidly from preheat | 815 | 1500 | 1095-1230 | 2000-2250 | 2-5 | O | 565-650 | 1050-1200 |
| H25 | Rapidly from preheat | 815 | 1500 | 1150-1260 | 2100-2300 | 2-5 | A or O | 565-675 | 1050-1250 |
| H26 | Rapidly from preheat | 870 | 1600 | 1175-1260 | 2150-2300 | 2-5 | O, A or S | 565-675 | 1050-1250 |
Molybdenum Hot-Work Steels 2 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| H41, H43 | Rapidly from preheat | 730-845 | 1350-1550 | 1095-1190 | 2000-2175 | 2-5 | O, A or S | 565-650 | 1050-1200 |
| H42 | Rapidly from preheat | 730-845 | 1350-1550 | 1120-1220 | 2050-2225 | 2-5 | O, A or S | 565-650 | 1050-1200 |
High-Carbon, High-Chromium Cold-Work Steels 4 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| D1, D5 | Very slowly | 815 | 1500 | 980-1025 | 1800-1875 | 15-45 | A | 205-540 | 400-1000 |
| D3 | Very slowly | 815 | 1500 | 925-980 | 1700-1800 | 15-45 | O | 205-540 | 400-1000 |
| D4 | Very slowly | 815 | 1500 | 970-1010 | 1775-1850 | 15-45 | A | 205-540 | 400-1000 |
| D7 | Very slowly | 815 | 1500 | 1010-1065 | 1850-1950 | 30-60 | A | 150-540 | 300-1000 |
Medium-Alloy, Air-Hardening Cold-Work Steels 8 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| A2 | Slowly | 790 | 1450 | 925-980 | 1700-1800 | 20-45 | A | 175-540 | 350-1000 |
| A3 | Slowly | 790 | 1450 | 955-980 | 1750-1800 | 25-60 | A | 175-540 | 350-1000 |
| A4 | Slowly | 675 | 1250 | 815-870 | 1500-1600 | 20-45 | A | 175-425 | 350-800 |
| A6 | Slowly | 650 | 1200 | 830-870 | 1525-1600 | 20-45 | A | 150-425 | 300-800 |
| A7 | Very slowly | 815 | 1500 | 955-980 | 1750-1800 | 30-60 | A | 150-540 | 300-1000 |
| A8 | Slowly | 790 | 1450 | 980-1010 | 1800-1850 | 20-45 | A | 175-595 | 350-1100 |
| A9 | Slowly | 790 | 1450 | 980-1025 | 1800-1875 | 20-45 | A | 510-620 | 950-1150 |
| A10 | Slowly | 650 | 1200 | 790-815 | 1450-1500 | 30-60 | A | 175-425 | 350-800 |
Oil-Hardening Cold-Work Steels 4 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| O1 | Slowly | 650 | 1200 | 790-815 | 1450-1500 | 10-30 | O | 175-260 | 350-500 |
| O2 | Slowly | 650 | 1200 | 760-800 | 1400-1475 | 5-20 | O | 175-260 | 350-500 |
| O6 | Slowly | — | — | 790-815 | 1450-1500 | 10-30 | O | 175-315 | 350-600 |
| O7 | Slowly | 650 | 1200 | W: 790-830 / O: 845-885 | W: 1450-1525 / O: 1550-1625 | 10-30 | O or W | 175-290 | 350-550 |
Shock-Resisting Steels 4 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| S1 | Slowly | — | — | 900-955 | 1650-1750 | 15-45 | O | 205-650 | 400-1200 |
| S2 | Slowly | 650 (f) | 1200 (f) | 845-900 | 1550-1650 | 5-20 | B or W | 175-425 | 350-800 |
| S5 | Slowly | 760 | 1400 | 870-925 | 1600-1700 | 5-20 | O | 175-425 | 350-800 |
| S7 | Slowly | 650-705 | 1200-1300 | 925-955 | 1700-1750 | 15-45 | A or O | 205-260 | 400-500 |
Mold Steels 7 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| P2 | — | — | — | 900-925 (g) / 830-845 (h) | 1650-1750 (g) / 1525-1550 (h) | 15 | O | 175-260 | 350-500 |
| P3 | — | — | — | 900-925 (g) / 800-830 (h) | 1650-1700 (g) / 1475-1525 (h) | 15 | O | 175-260 | 350-500 |
| P4 | — | — | — | 970-995 (g) / 970-995 (h) | 1775-1825 (g) / 1775-1825 (h) | 15 | A | 175-480 | 350-900 |
| P5 | — | — | — | 900-925 (g) / 845-870 (h) | 1650-1700 (g) / 1550-1600 (h) | 15 | O or W | 175-260 | 350-500 |
| P6 | — | — | — | 900-925 (g) / 790-815 (h) | 1650-1700 (g) / 1450-1500 (h) | 15 | A or O | 175-230 | 350-450 |
| P20 | — | — | — | 870-900 (h) / 815-870 | 1600-1650 (h) / 1500-1600 | 15 | O | 480-595 (i) | 900-1100 (i) |
| P21 (j) | Slowly | Do not preheat | — | 705-730 | 1300-1350 | 60-180 | A or O | 510-550 | 950-1025 |
Low-Alloy Special-Purpose Steels 3 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| L2 | Slowly | — | — | W: 790-845 / O: 845-925 | W: 1450-1550 / O: 1550-1700 | 10-30 | O or W | 175-540 | 350-1000 |
| L3 | Slowly | — | — | W: 775-815 / O: 815-870 | W: 1425-1500 / O: 1500-1600 | 10-30 | O or W | 175-315 | 350-600 |
| L6 | Slowly | — | — | 790-845 | 1450-1550 | 10-30 | O | 175-540 | 350-1000 |
Carbon-Tungsten Special-Purpose Steels 1 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| F1, F2 | Slowly | 650 | 1200 | 790-870 | 1450-1600 | 15 | W or B | 175-260 | 350-500 |
Water-Hardening Steels 1 grades ▾
| Type | Rate of heating | Preheat °C | Preheat °F | Hardening °C | Hardening °F | Time, min | Quench (a) | Tempering °C | Tempering °F |
|---|---|---|---|---|---|---|---|---|---|
| W1, W2, W3 | Slowly | 565-650 (k) | 1050-1200 (k) | 760-845 | 1400-1550 | 10-30 | B or W | 175-345 | 350-650 |
Notes & References
- (a) O, oil quench; A, air cool; S, salt bath quench; W, water quench; B, brine quench.
- (b) When the high-temperature heating is carried out in a salt bath, the range of temperatures should be about 14 °C (25 °F) lower than given here.
- (c) Double tempering recommended for not less than 1 h at temperature each time.
- (d) Triple tempering recommended for not less than 1 h at temperature each time.
- (e) Times apply to open furnace heat treatment. For pack hardening, a common rule is to heat 1.2 min per mm (30 min per in.) of cross section of the pack.
- (f) Preferable for large tools to minimize decarburization.
- (g) Carburizing temperature.
- (h) After carburizing.
- (i) Carburized per case hardness.
- (j) P21 is a precipitation-hardening steel having a thermal treatment that involves solution treating and aging rather than hardening and tempering.
- (k) Recommended for large tools and tools with intricate sections.
Supply Scope & Technical Reference Note
Aobo Steel supplies tool steel in an annealed condition and does not provide final heat-treatment services such as hardening, quenching, cryogenic treatment, or tempering.
The heat treatment parameters, hardness data, and process recommendations in this reference are provided as general technical support for our customers. Actual heat-treatment results may vary depending on furnace capacity, section size, tool geometry, material condition, quenching practice, and process control. Final heat-treatment procedures and validation should be performed by the customer’s heat-treatment facility in accordance with the specific tooling application and production requirements.
Data source: ASM Handbook, Wrought Tool Steels (revised by Alan M. Bayer, Teledyne Vasco, and Lee R. Walton, Latrobe Steel Company). Tables 8 & 9. Data compiled from public references and industry standards.