Tool Steel Composition Chart
Chemical composition limits for the principal AISI tool steel types, the M, T, H, A, D, O, S, L, P and W groups. Values are cast or heat analysis ranges in weight percent; a single value is a maximum unless followed by “min”.
Tool steel composition chart, printable PDF
Three A4 pages with all 76 grades in the M, T, H, A, D, O, S, L, P and W groups, the composition limits, the table notes and the source reference.
| AISI | UNS | C | Mn | Si | Cr | Ni | Mo | W | V | Co |
|---|---|---|---|---|---|---|---|---|---|---|
| Molybdenum high-speed steels (M series) | ||||||||||
| M1 | T11301 | 0.78-0.88 | 0.15-0.40 | 0.20-0.50 | 3.50-4.00 | 0.30 max | 8.20-9.20 | 1.40-2.10 | 1.00-1.25 | — |
| M2 | T11302 | 0.78-0.88; 0.95-1.05 | 0.15-0.40 | 0.20-0.45 | 3.75-4.50 | 0.30 max | 4.50-5.50 | 5.50-6.75 | 1.75-2.20 | — |
| M3, class 1 | T11313 | 1.00-1.10 | 0.15-0.40 | 0.20-0.45 | 3.75-4.50 | 0.30 max | 4.75-6.50 | 5.00-6.75 | 2.25-2.75 | — |
| M3, class 2 | T11323 | 1.15-1.25 | 0.15-0.40 | 0.20-0.45 | 3.75-4.50 | 0.30 max | 4.75-6.50 | 5.00-6.75 | 2.75-3.75 | — |
| M4 | T11304 | 1.25-1.40 | 0.15-0.40 | 0.20-0.45 | 3.75-4.75 | 0.30 max | 4.25-5.50 | 5.25-6.50 | 3.75-4.50 | — |
| M7 | T11307 | 0.97-1.05 | 0.15-0.40 | 0.20-0.55 | 3.50-4.00 | 0.30 max | 8.20-9.20 | 1.40-2.10 | 1.75-2.25 | — |
| M10 | T11310 | 0.84-0.94; 0.95-1.05 | 0.10-0.40 | 0.20-0.45 | 3.75-4.50 | 0.30 max | 7.75-8.50 | — | 1.80-2.20 | — |
| M30 | T11330 | 0.75-0.85 | 0.15-0.40 | 0.20-0.45 | 3.50-4.25 | 0.30 max | 7.75-9.00 | 1.30-2.30 | 1.00-1.40 | 4.50-5.50 |
| M33 | T11333 | 0.85-0.92 | 0.15-0.40 | 0.15-0.50 | 3.50-4.00 | 0.30 max | 9.00-10.00 | 1.30-2.10 | 1.00-1.35 | 7.75-8.75 |
| M34 | T11334 | 0.85-0.92 | 0.15-0.40 | 0.20-0.45 | 3.50-4.00 | 0.30 max | 7.75-9.20 | 1.40-2.10 | 1.90-2.30 | 7.75-8.75 |
| M35 | T11335 | 0.82-0.88 | 0.15-0.40 | 0.20-0.45 | 3.75-4.50 | 0.30 max | 4.50-5.50 | 5.50-6.75 | 1.75-2.20 | 4.50-5.50 |
| M36 | T11336 | 0.80-0.90 | 0.15-0.40 | 0.20-0.45 | 3.75-4.50 | 0.30 max | 4.50-5.50 | 5.50-6.50 | 1.75-2.25 | 7.75-8.75 |
| M41 | T11341 | 1.05-1.15 | 0.20-0.60 | 0.15-0.50 | 3.75-4.50 | 0.30 max | 3.25-4.25 | 6.25-7.00 | 1.75-2.25 | 4.75-5.75 |
| M42 | T11342 | 1.05-1.15 | 0.15-0.40 | 0.15-0.65 | 3.50-4.25 | 0.30 max | 9.00-10.00 | 1.15-1.85 | 0.95-1.35 | 7.75-8.75 |
| M43 | T11343 | 1.15-1.25 | 0.20-0.40 | 0.15-0.65 | 3.50-4.25 | 0.30 max | 7.50-8.50 | 2.25-3.00 | 1.50-1.75 | 7.75-8.75 |
| M44 | T11344 | 1.10-1.20 | 0.20-0.40 | 0.30-0.55 | 4.00-4.75 | 0.30 max | 6.00-7.00 | 5.00-5.75 | 1.85-2.20 | 11.00-12.25 |
| M46 | T11346 | 1.22-1.30 | 0.20-0.40 | 0.40-0.65 | 3.70-4.20 | 0.30 max | 8.00-8.50 | 1.90-2.20 | 3.00-3.30 | 7.80-8.80 |
| M47 | T11347 | 1.05-1.15 | 0.15-0.40 | 0.20-0.45 | 3.50-4.00 | 0.30 max | 9.25-10.00 | 1.30-1.80 | 1.15-1.35 | 4.75-5.25 |
| M48 | T11348 | 1.42-1.52 | 0.15-0.40 | 0.15-0.40 | 3.50-4.00 | 0.30 max | 4.75-5.50 | 9.50-10.50 | 2.75-3.25 | 8.00-10.00 |
| M62 | T11362 | 1.25-1.35 | 0.15-0.40 | 0.15-0.40 | 3.50-4.00 | 0.30 max | 10.00-11.00 | 5.75-6.50 | 1.80-2.10 | — |
| Tungsten high-speed steels (T series) | ||||||||||
| T1 | T12001 | 0.65-0.80 | 0.10-0.40 | 0.20-0.40 | 3.75-4.50 | 0.30 max | — | 17.25-18.75 | 0.90-1.30 | — |
| T2 | T12002 | 0.80-0.90 | 0.20-0.40 | 0.20-0.40 | 3.75-4.50 | 0.30 max | 1.00 max | 17.50-19.00 | 1.80-2.40 | — |
| T4 | T12004 | 0.70-0.80 | 0.10-0.40 | 0.20-0.40 | 3.75-4.50 | 0.30 max | 0.40-1.00 | 17.50-19.00 | 0.80-1.20 | 4.25-5.75 |
| T5 | T12005 | 0.75-0.85 | 0.20-0.40 | 0.20-0.40 | 3.75-5.00 | 0.30 max | 0.50-1.25 | 17.50-19.00 | 1.80-2.40 | 7.00-9.50 |
| T6 | T12006 | 0.75-0.85 | 0.20-0.40 | 0.20-0.40 | 4.00-4.75 | 0.30 max | 0.40-1.00 | 18.50-21.00 | 1.50-2.10 | 11.00-13.00 |
| T8 | T12008 | 0.75-0.85 | 0.20-0.40 | 0.20-0.40 | 3.75-4.50 | 0.30 max | 0.40-1.00 | 13.25-14.75 | 1.80-2.40 | 4.25-5.75 |
| T15 | T12015 | 1.50-1.60 | 0.15-0.40 | 0.15-0.40 | 3.75-5.00 | 0.30 max | 1.00 max | 11.75-13.00 | 4.50-5.25 | 4.75-5.25 |
| Intermediate high-speed steels | ||||||||||
| M50 | T11350 | 0.78-0.88 | 0.15-0.45 | 0.20-0.60 | 3.75-4.50 | 0.30 max | 3.90-4.75 | — | 0.80-1.25 | — |
| M52 | T11352 | 0.85-0.95 | 0.15-0.45 | 0.20-0.60 | 3.50-4.30 | 0.30 max | 4.00-4.90 | 0.75-1.50 | 1.65-2.25 | — |
| Chromium hot-work steels (H10-H19) | ||||||||||
| H10 | T20810 | 0.35-0.45 | 0.25-0.70 | 0.80-1.20 | 3.00-3.75 | 0.30 max | 2.00-3.00 | — | 0.25-0.75 | — |
| H11 | T20811 | 0.33-0.43 | 0.20-0.50 | 0.80-1.20 | 4.75-5.50 | 0.30 max | 1.10-1.60 | — | 0.30-0.60 | — |
| H12 | T20812 | 0.30-0.40 | 0.20-0.50 | 0.80-1.20 | 4.75-5.50 | 0.30 max | 1.25-1.75 | 1.00-1.70 | 0.50 max | — |
| H13 | T20813 | 0.32-0.45 | 0.20-0.50 | 0.80-1.20 | 4.75-5.50 | 0.30 max | 1.10-1.75 | — | 0.80-1.20 | — |
| H14 | T20814 | 0.35-0.45 | 0.20-0.50 | 0.80-1.20 | 4.75-5.50 | 0.30 max | — | 4.00-5.25 | — | — |
| H19 | T20819 | 0.32-0.45 | 0.20-0.50 | 0.20-0.50 | 4.00-4.75 | 0.30 max | 0.30-0.55 | 3.75-4.50 | 1.75-2.20 | 4.00-4.50 |
| Tungsten hot-work steels (H21-H26) | ||||||||||
| H21 | T20821 | 0.26-0.36 | 0.15-0.40 | 0.15-0.50 | 3.00-3.75 | 0.30 max | — | 8.50-10.00 | 0.30-0.60 | — |
| H22 | T20822 | 0.30-0.40 | 0.15-0.40 | 0.15-0.40 | 1.75-3.75 | 0.30 max | — | 10.00-11.75 | 0.25-0.50 | — |
| H23 | T20823 | 0.25-0.35 | 0.15-0.40 | 0.15-0.60 | 11.00-12.75 | 0.30 max | — | 11.00-12.75 | 0.75-1.25 | — |
| H24 | T20824 | 0.42-0.53 | 0.15-0.40 | 0.15-0.40 | 2.50-3.50 | 0.30 max | — | 14.00-16.00 | 0.40-0.60 | — |
| H25 | T20825 | 0.22-0.32 | 0.15-0.40 | 0.15-0.40 | 3.75-4.50 | 0.30 max | — | 14.00-16.00 | 0.40-0.60 | — |
| H26 | T20826 | 0.45-0.55 (b) | 0.15-0.40 | 0.15-0.40 | 3.75-4.50 | 0.30 max | — | 17.25-19.00 | 0.75-1.25 | — |
| Molybdenum hot-work steels | ||||||||||
| H42 | T20842 | 0.55-0.70 (b) | 0.15-0.40 | — | 3.75-4.50 | 0.30 max | 4.50-5.50 | 5.50-6.75 | 1.75-2.20 | — |
| Air-hardening cold-work steels (A series) | ||||||||||
| A2 | T30102 | 0.95-1.05 | 1.00 max | 0.50 max | 4.75-5.50 | 0.30 max | 0.90-1.40 | — | 0.15-0.50 | — |
| A3 | T30103 | 1.20-1.30 | 0.40-0.60 | 0.50 max | 4.75-5.50 | 0.30 max | 0.90-1.40 | — | 0.80-1.40 | — |
| A4 | T30104 | 0.95-1.05 | 1.80-2.20 | 0.50 max | 0.90-2.20 | 0.30 max | 0.90-1.40 | — | — | — |
| A6 | T30106 | 0.65-0.75 | 1.80-2.50 | 0.50 max | 0.90-1.20 | 0.30 max | 0.90-1.40 | — | — | — |
| A7 | T30107 | 2.00-2.85 | 0.80 max | 0.50 max | 5.00-5.75 | 0.30 max | 0.90-1.40 | 0.50-1.50 | 3.90-5.15 | — |
| A8 | T30108 | 0.50-0.60 | 0.50 max | 0.75-1.10 | 4.75-5.50 | 0.30 max | 1.15-1.65 | 1.00-1.50 | — | — |
| A9 | T30109 | 0.45-0.55 | 0.50 max | 0.95-1.15 | 4.75-5.50 | 1.25-1.75 | 1.30-1.80 | — | 0.80-1.40 | — |
| A10 | T30110 | 1.25-1.50 (c) | 1.60-2.10 | 1.00-1.50 | — | 1.55-2.05 | 1.25-1.75 | — | — | — |
| High-carbon, high-chromium cold-work steels (D series) | ||||||||||
| D2 | T30402 | 1.40-1.60 | 0.60 max | 0.60 max | 11.00-13.00 | 0.30 max | 0.70-1.20 | — | 1.10 max | — |
| D3 | T30403 | 2.00-2.35 | 0.60 max | 0.60 max | 11.00-13.50 | 0.30 max | — | 1.00 max | 1.00 max | — |
| D4 | T30404 | 2.05-2.40 | 0.60 max | 0.60 max | 11.00-13.00 | 0.30 max | 0.70-1.20 | — | 1.00 max | — |
| D5 | T30405 | 1.40-1.60 | 0.60 max | 0.60 max | 11.00-13.00 | 0.30 max | 0.70-1.20 | — | 1.00 max | 2.50-3.50 |
| D7 | T30407 | 2.15-2.50 | 0.60 max | 0.60 max | 11.50-13.50 | 0.30 max | 0.70-1.20 | — | 3.80-4.40 | — |
| Oil-hardening cold-work steels (O series) | ||||||||||
| O1 | T31501 | 0.85-1.00 | 1.00-1.40 | 0.50 max | 0.40-0.60 | 0.30 max | — | 0.40-0.60 | 0.30 max | — |
| O2 | T31502 | 0.85-0.95 | 1.40-1.80 | 0.50 max | 0.50 max | 0.30 max | 0.30 max | — | 0.30 max | — |
| O6 | T31506 | 1.25-1.55 (c) | 0.30-1.10 | 0.55-1.50 | 0.30 max | 0.30 max | 0.20-0.30 | — | — | — |
| O7 | T31507 | 1.10-1.30 | 1.00 max | 0.60 max | 0.35-0.85 | 0.30 max | 0.30 max | 1.00-2.00 | 0.40 max | — |
| Shock-resisting steels (S series) | ||||||||||
| S1 | T41901 | 0.40-0.55 | 0.10-0.40 | 0.15-1.20 | 1.00-1.80 | 0.30 max | 0.50 max | 1.50-3.00 | 0.15-0.30 | — |
| S2 | T41902 | 0.40-0.55 | 0.30-0.50 | 0.90-1.20 | — | 0.30 max | 0.30-0.60 | — | 0.50 max | — |
| S5 | T41905 | 0.50-0.65 | 0.60-1.00 | 1.75-2.25 | 0.50 max | — | 0.20-1.35 | — | 0.35 max | — |
| S6 | T41906 | 0.40-0.50 | 1.20-1.50 | 2.00-2.50 | 1.20-1.50 | — | 0.30-0.50 | — | 0.20-0.40 | — |
| S7 | T41907 | 0.45-0.55 | 0.20-0.90 | 0.20-1.00 | 3.00-3.50 | — | 1.30-1.80 | — | 0.20-0.30 (d) | — |
| Low-alloy special-purpose steels (L series) | ||||||||||
| L2 | T61202 | 0.45-1.00 (b) | 0.10-0.90 | 0.50 max | 0.70-1.20 | — | 0.25 max | — | 0.10-0.30 | — |
| L6 | T61206 | 0.65-0.75 | 0.25-0.80 | 0.50 max | 0.60-1.20 | 1.25-2.00 | 0.50 max | — | 0.20-0.30 (d) | — |
| Low-carbon mold steels (P series) | ||||||||||
| P2 | T51602 | 0.10 max | 0.10-0.40 | 0.10-0.40 | 0.75-1.25 | 0.10-0.50 | 0.15-0.40 | — | — | — |
| P3 | T51603 | 0.10 max | 0.20-0.60 | 0.40 max | 0.40-0.75 | 1.00-1.50 | — | — | — | — |
| P4 | T51604 | 0.12 max | 0.20-0.60 | 0.10-0.40 | 4.00-5.25 | — | 0.40-1.00 | — | — | — |
| P5 | T51605 | 0.10 max | 0.20-0.60 | 0.40 max | 2.00-2.50 | 0.35 max | — | — | — | — |
| P6 | T51606 | 0.05-0.15 | 0.35-0.70 | 0.10-0.40 | 1.25-1.75 | 3.25-3.75 | — | — | — | — |
| P20 | T51620 | 0.28-0.40 | 0.60-1.00 | 0.20-0.80 | 1.40-2.00 | — | 0.30-0.55 | — | — | — |
| P21 | T51621 | 0.18-0.22 | 0.20-0.40 | 0.20-0.40 | 0.50 max | 3.90-4.25 | — | — | 0.15-0.25 | — |
| Water-hardening tool steels (W series) | ||||||||||
| W1 | T72301 | 0.70-1.50 (e) | 0.10-0.40 | 0.10-0.40 | 0.15 max | 0.20 max | 0.10 max | 0.15 max | 0.10 max | — |
| W2 | T72302 | 0.85-1.50 (e) | 0.10-0.40 | 0.10-0.40 | 0.15 max | 0.20 max | 0.10 max | 0.15 max | 0.15-0.35 | — |
| W5 | T72305 | 1.05-1.15 | 0.10-0.40 | 0.10-0.40 | 0.40-0.60 | 0.20 max | 0.10 max | 0.15 max | 0.10 max | — |
- (a) All steels except group W contain 0.25% max Cu, 0.03% max P and 0.03% max S; group W steels contain 0.20% max Cu, 0.025% max P and 0.025% max S. Where specified, sulfur may be increased to 0.06–0.15% to improve machinability of group A, D, H, M and T steels.
- (b) Available in several carbon ranges.
- (c) Contains free graphite in the microstructure.
- (d) Optional.
- (e) Specified carbon ranges are designated by suffix numbers.
Table notes
P21 additionally contains 1.05–1.25% Al (aluminum), specified for resistance to heat checking; Al is not shown as a separate column above.
Two values in the source table were printed with a missing decimal point and are corrected here: M10 chromium reads “3.75-450” in the source and is given as 3.75–4.50; A9 molybdenum reads “1.30-180” and is given as 1.30–1.80.
Composition limits are heat analysis values from the source. Product analysis tolerances may apply — confirm the governing standard (ASTM A681, A600 or A686, or the applicable national standard) with your supplier before ordering.
Grade-level limits for individual steels, such as the H13 chemical composition range, are listed on the grade pages.
Hardness, toughness and wear resistance for these grades are compared on the tool steel properties chart, and the preheat, hardening and tempering schedule for each family is in the tool steel heat treatment guide.
DIN, JIS and GB designations for these AISI grades are listed on the tool steel equivalent grades page. The same limits for other families are on the stainless, alloy and carbon steel composition charts.
Related reference pages
How to select tool steels · Processing and service characteristics · Annealing and normalizing temperature chart · Obsolete tool steel grades
Source: ASM Handbook, Volume 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys, Table 1 “Composition limits of principal types of tool steels” (10th ed.). Reference data for comparison — verify the applicable standard before ordering.