P/M Tool Steel Composition Chart, High Speed, Cold Work and Hot Work Grades
The commercial powder metallurgy tool steels are sold under three families of trade name, CPM, ASP and HAP, and the compositions below are the ones those names stand for. The highest value of the table is that it settles a common question on the buying side. A CPM grade usually carries the analysis of a conventional grade of the same AISI type, so the price difference is not bought in the chemistry, it is bought in how the carbide is delivered. The three tables cover the high speed P/M grades, the cold work P/M grades and the hot work P/M grades, each with the hardness range the source prints for it.
P/M high speed tool steels
This is the family the powder route was developed for. The conventional high speed steels are the most heavily alloyed tool steels made, so they are also the ones that segregate worst on casting, and the difference between a CPM grade and the ingot grade of the same analysis is the difference between a fine even carbide field and a banded one. The two letters codes that follow a grade name are sulfur levels, and they matter to the shop rather than to the heat treater. HCHS is high carbon and high sulfur, HS is high sulfur, and the sulfur is there as sulfide inclusions that break the chip and raise machinability. The same trick is used on conventional grades and the P/M route delivers the sulfide inclusions at the same fine scale as the carbides.
Table 1a. Commercial P/M high speed tool steel compositions, wt%
| Trade name | AISI | C | Cr | W | Mo | V | Co | S | Other | Hardness, HRC |
|---|---|---|---|---|---|---|---|---|---|---|
| ASP 23 | M3 | 1.28 | 4.20 | 6.40 | 5.00 | 3.10 | — | — | — | 65-67 |
| ASP 30 | — | 1.28 | 4.20 | 6.40 | 5.00 | 3.10 | 8.5 | — | — | 66-68 |
| ASP 60 | — | 2.30 | 4.00 | 6.50 | 7.00 | 6.50 | 10.50 | — | — | 67-69 |
| CPM Rex M2HCHS | M2 | 1.00 | 4.15 | 6.40 | 5.00 | 2.00 | — | 0.27 | — | 64-66 |
| CPM Rex M3HCHS | M3 | 1.30 | 4.00 | 6.25 | 5.00 | 3.00 | — | 0.27 | — | 65-67 |
| CPM Rex M4 | M4 | 1.35 | 4.25 | 5.75 | 4.50 | 4.00 | — | 0.06 | — | 64-66 |
| CPM Rex M4HS | M4 | 1.35 | 4.25 | 5.75 | 4.50 | 4.00 | — | 0.22 | — | 64-66 |
| CPM Rex M35HCHS | M35 | 1.00 | 4.15 | 6.00 | 5.00 | 2.00 | 5.0 | 0.27 | — | 65-67 |
| CPM Rex M42 | M42 | 1.10 | 3.75 | 1.50 | 9.50 | 1.15 | 8.0 | — | — | 66-68 |
| CPM Rex 45 | — | 1.30 | 4.00 | 6.25 | 5.00 | 3.00 | 8.25 | 0.03 | — | 66-68 |
| CPM Rex 45HS | — | 1.30 | 4.00 | 6.25 | 5.00 | 3.00 | 8.25 | 0.22 | — | 66-68 |
| CPM Rex 20 | M62 | 1.30 | 3.75 | 6.25 | 10.50 | 2.00 | — | — | — | 66-68 |
| CPM Rex 25 | M61 | 1.80 | 4.00 | 12.50 | 6.50 | 5.00 | — | — | — | 67-69 |
| CPM Rex T15 | T15 | 1.55 | 4.00 | 12.25 | — | 5.00 | 5.0 | 0.06 | — | 65-67 |
| CPM Rex T15HS | T15 | 1.55 | 4.00 | 12.25 | — | 5.00 | 5.0 | 0.22 | — | 65-67 |
| CPM Rex 76 | M48 | 1.50 | 3.75 | 10.0 | 5.25 | 3.10 | 9.00 | 0.06 | — | 67-69 |
| CPM Rex 76HS | M48 | 1.50 | 3.75 | 10.0 | 5.25 | 3.10 | 9.00 | 0.22 | — | 67-69 |
| HAP 10 | — | 1.35 | 5.0 | 3.0 | 6.0 | 3.8 | — | — | — | 64-66 |
| HAP 40 | — | 1.30 | 4.0 | 6.0 | 5.0 | 3.0 | 8.0 | — | — | — |
| HAP 50 | — | 1.50 | 4.0 | 8.0 | 6.0 | 4.0 | 8.0 | — | — | — |
| HAP 60 | — | 2.00 | 4.0 | 10.0 | 4.0 | 7.0 | 12.0 | — | — | — |
| HAP 70 | — | 2.00 | 4.0 | 12.0 | 10.0 | 4.5 | 12.0 | — | — | — |
| KHA 33N | — | 0.95 | 4.0 | 6.0 | 6.0 | 3.5 | — | — | 0.60N | 65-66 |
Source, ASM Handbook Vol.1, article P/M Tool Steels, Table 1. A dash means the source lists no value for that cell. Grades ASP 23 and ASP 30 share one analysis apart from cobalt, which is the point of the pair.
P/M cold work tool steels
The cold work P/M grades are the ones bought for wear rather than for hot hardness. CPM 9V, CPM 10V and the equivalent vanadium grades carry their vanadium as hard MC carbide, which is the phase that resists abrasive wear, and the P/M route is what makes that much vanadium workable, because a conventionally cast steel at this vanadium level would be a carbide network rather than a tool steel. CPM 440V is the stainless member of the group and it is the grade to look at when both corrosion resistance and wear resistance are wanted in one tool. The wear and toughness these compositions produce are measured on the P/M tool steel properties page, which carries the crossed-cylinder wear and Charpy data for CPM 9V and CPM 10V against D2 and M2.
Table 1b. Commercial P/M cold work tool steel compositions, wt%
| Trade name | AISI | C | Cr | W | Mo | V | Co | S | Other | Hardness, HRC |
|---|---|---|---|---|---|---|---|---|---|---|
| CPM 9V | — | 1.78 | 5.25 | — | 1.30 | 9.00 | — | 0.03 | — | 53-55 |
| CPM 10V | A11 | 2.45 | 5.25 | — | 1.30 | 9.75 | — | 0.07 | — | 60-62 |
| CPM 440V | — | 2.15 | 17.50 | — | 0.50 | 5.75 | — | — | — | 57-59 |
| Vanadis 4 | — | 1.50 | 8.00 | — | 1.50 | 4.00 | — | — | — | 59-63 |
Source, ASM Handbook Vol.1, article P/M Tool Steels, Table 1. The AISI column is empty for CPM 9V, CPM 440V and Vanadis 4 because the source prints no designation for them. CPM 10V carries A11.
P/M hot work tool steels
Only three hot work grades appear in this table and they are all built on the same idea, which is to take a die steel that normally fails by thermal fatigue and give it a clean, even carbide population, so the crack that starts at a coarse carbide does not have a band to run along. CPM H13 carries the analysis of the conventional H13 and is the plainest replacement of the three. CPM H19 adds tungsten and cobalt for hot hardness at the top of the working range. CPM H19V raises vanadium from 2.10 to 4.00 per cent for wear resistance in the same hot work role, at the cost of machinability.
Table 1c. Commercial P/M hot work tool steel compositions, wt%
| Trade name | AISI | C | Cr | W | Mo | V | Co | S | Other | Hardness, HRC |
|---|---|---|---|---|---|---|---|---|---|---|
| CPM H13 | H13 | 0.40 | 5.00 | — | 1.30 | 1.05 | — | — | — | 42-48 |
| CPM H19 | H19 | 0.40 | 4.25 | 4.25 | 0.40 | 2.10 | 4.25 | — | — | 44-52 |
| CPM H19V | — | 0.80 | 4.25 | 4.25 | 0.40 | 4.00 | 4.25 | — | — | 44-56 |
Source, ASM Handbook Vol.1, article P/M Tool Steels, Table 1. Footnote to the source table, (a) HCHS means high carbon, high sulfur and HS means high sulfur. KHA 33N carries 0.60 per cent nitrogen in the Other column.
How to read these tables against a mill certificate
A composition table is a specification window, not a heat analysis. Two heats of the same grade will differ in the last decimal place and still both be to specification, and the carbon figure in particular moves by a few hundredths of a per cent from heat to heat. Where the number matters, the useful document is the mill test certificate for the specific heat, not a table like this one. The hardness column stays useful in the other direction. It is the hardness range the source prints for the grade, and it is what a tool drawing should be written against, because a grade ordered harder than its range allows will chip and one ordered softer than the job needs will wear.
Composition data is for general reference only. Actual values vary by standard, mill, and heat number. Confirm against the material test certificate (MTC) or contact Aobo Steel.
The analyses above are the published compositions of the commercial grades. Where the same analysis is available as an ingot-cast steel, the comparison is worth making before the order is placed, because for a cold work die at moderate production volume the conventional grade is the cheaper route to the same tool and the P/M premium buys nothing the die will use. The conventional grades and their equivalents are collected on the high speed steel property chart and the P/M high speed steel composition page, and the carbide types each of these analyses produces are set out on the carbide volume fractions page.
Source: ASM Handbook, Vol 1, Properties and Selection: Irons, Steels and High-Performance Alloys.