Tool Steel Hardening and Tempering Chart
Recommended hardening and tempering practice for the principal AISI tool steels — preheat and austenitizing (hardening) temperatures, soak time, quenching medium and tempering temperature, grouped by steel family. Values are given in both °C and °F as printed in the source.
| Tipo | Rate of heating | Endurecimiento | Temple medium(a) | Tempering temperature | |||||
|---|---|---|---|---|---|---|---|---|---|
| Preheat temperature | Hardening temperature | Time at temperature, min | °C | °F | |||||
| °C | °F | °C | °F | ||||||
| Aceros rápidos de molibdeno | |||||||||
| M1, M7, M10 | Rapidly from preheat | 730-845 | 1350-1550 | 1175-1220 | 2150-2225 (b) | 2-5 | O, A, or S | 540-595 (do) | 1000-1100 (do) |
| M2 | Rapidly from preheat | 730-845 | 1350-1550 | 1190-1230 | 2175-2250 (b) | 2-5 | O, A, or S | 540-595 (do) | 1000-1100 (do) |
| 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 (do) | 1000-1100 (do) |
| M36 | Rapidly from preheat | 730-845 | 1350-1550 | 1220-1245 (b) | 2225-2275 (b) | 2-5 | O, A, or S | 540-595 (do) | 1000-1100 (do) |
| 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) |
| Aceros de tungsteno de alta velocidad | |||||||||
| 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 (do) | 1000-1100 (do) |
| T5, T6 | Rapidly from preheat | 815-870 | 1500-1600 | 1275-1300 (b) | 2325-2375 (b) | 2-5 | O, A, or S | 540-595 (do) | 1000-1100 (do) |
| 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) |
| Aceros intermedios de alta velocidad | |||||||||
| 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 |
| Aceros al cromo para trabajo en caliente | |||||||||
| H10 | Moderately from preheat | 815 | 1500 | 1010-1040 | 1850-1900 | 15-40 (mi) | A | 540-650 | 1000-1200 |
| H11, H12 | Moderately from preheat | 815 | 1500 | 995-1025 | 1825-1875 | 15-40 (mi) | A | 540-650 | 1000-1200 |
| H13 | Moderately from preheat | 815 | 1500 | 995-1040 | 1825-1900 | 15-40 (mi) | A | 540-650 | 1000-1200 |
| H14 | Moderately from preheat | 815 | 1500 | 1010-1065 | 1850-1950 | 15-40 (mi) | A | 540-650 | 1000-1200 |
| H19 | Moderately from preheat | 815 | 1500 | 1095-1205 | 2000-2200 | 2-5 | A or O | 540-705 | 1000-1300 |
| Aceros de tungsteno para trabajo en caliente | |||||||||
| 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 |
| Aceros para trabajo en caliente con molibdeno | |||||||||
| 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 |
| Aceros de alto contenido de carbono y cromo para trabajo en frío | |||||||||
| 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 | |||||||||
| 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 |
| Aceros para trabajo en frío endurecibles con aceite | |||||||||
| 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 | 790-830 845-885 | W: 1450-1525 O: 1550-1625 | 10-30 | O or W | 175-290 | 350-550 |
| Aceros resistentes a los golpes | |||||||||
| 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 | 205-620 | 400-1150 |
| Mold steels | |||||||||
| P2 | — | 900-925 (g) | 1650-1750 (g) | 830-845 (h) | 1525-1550 (h) | 15 | O | 175-260 | 350-500 |
| P3 | — | 900-925 (g) | 1650-1700 (g) | 800-830 (h) | 1475-1525 (h) | 15 | O | 175-260 | 350-500 |
| P4 | — | 970-995 (g) | 1775-1825 (g) | 970-995 (h) | 1775-1825 (h) | 15 | A | 175-480 | 350-900 |
| P5 | — | 900-925 (g) | 1650-1700 (g) | 845-870 (h) | 1550-1600 (h) | 15 | O or W | 175-260 | 350-500 |
| P6 | — | 900-925 (g) | 1650-1700 (g) | 790-815 (h) | 1450-1500 (h) | 15 | A or O | 175-230 | 350-450 |
| P20 | — | 870-900 (h) | 1600-1650 (h) | 815-870 | 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 | |
| Aceros de baja aleación para usos especiales | |||||||||
| 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 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 | |||||||||
| F1, F2 | Slowly | 650 | 1200 | 790-870 | 1450-1600 | 15 | W or B | 175-260 | 350-500 |
| Water-hardening steels | |||||||||
| W1, W2, W3 | Slowly | 565-650 (k) | 1050-1200 (k) | 760-845 | 1400-1550 | 10-30 | B or W | 175-345 | 350-650 |
- (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.
- (do) 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.
- (mi) 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) Después de la carburación.
- (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.
Notas de la tabla
For O7, L2 and L3 the source gives two hardening ranges: the W: value applies to water quenching and the O: value to oil quenching. O7’s hardening ranges are printed in the W/O order in the °F column.
Two printed values are corrected here, following cross-checks against the source’s own companion values: A6’s hardening temperature is printed “1525n-;1600” in the e-book and is given as 1525–1600 °F (matching the 830–870 °C range); S7’s tempering range is printed 205–260 °C, which does not match its own 400–1150 °F column, and is given as 205–620 °C (620 °C = 1150 °F), matching the parallel tables in Aceros para herramientas (Roberts & Krauss, 5th ed.) and Machinery’s Handbook.
The source table does not include D2 among the high-carbon, high-chromium cold-work steels; see the Guía de tratamiento térmico del acero para herramientas D2 for that grade.
Hardening temperatures are austenitizing temperatures for conventional heat treatment; the quenching medium letter codes are explained in footnote (a). These are reference ranges — confirm production practice with your heat treater, since furnace type, load and section size all shift the working schedule. When a cycle does go wrong, the causes and the corrections are listed in the heat treatment troubleshooting chart.
Páginas de referencia relacionadas
Tool steel composition chart · Tool steel annealing & normalizing temperature chart · Tool steel processing & service characteristics · Tabla de propiedades del acero para herramientas · Tool steel equivalent grades · Tool steel heat treatment guide · Guía de tratamiento térmico del acero para herramientas D2 · acero para herramientas H13 · acero para herramientas D2 · acero para herramientas O1 · How to select tool steels
Source: ASM Handbook, Volume 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys, Table 9 “Hardening and tempering of tool steels” (10th ed.). Reference data for comparison — verify the applicable standard before ordering.