M36 vs M42
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
M36
Tool Steel
M36 applies the 8% cobalt treatment to the M2 base composition, giving red hardness close to M42 with a slightly different carbide balance. It is an older American cobalt grade still specified for heavy cutting tools.
Standards: AISI M36 · GB W6Mo5Cr4V2Co8 (near)
M42
Tool Steel
M42 is a molybdenum-cobalt high-speed steel reaching 67–70 HRC, the hardest of the widely stocked conventional HSS grades. It cuts hardened steels, superalloys and other materials that destroy M2 tooling.
Standards: DIN 1.3247 · AISI M42 · JIS SKH59 · GB W2Mo10Cr4VCo8
Chemical composition compared (%)
| Element | M36 | M42 |
|---|---|---|
| C | 0.80–0.90 | 1.05–1.15 |
| Si | ≤0.45 | ≤0.45 |
| Mn | ≤0.40 | ≤0.40 |
| Cr | 3.75–4.50 | 3.50–4.25 |
| Mo | 4.50–5.50 | 9.00–10.00 |
| W | 5.50–6.50 | 1.15–1.85 |
| V | 1.75–2.25 | 0.85–1.25 |
| Co | 7.75–8.75 | 7.75–8.75 |
Properties compared
| Property | M36 | M42 |
|---|---|---|
| Delivery condition | Annealed | Annealed |
| Hardness (hardened) | 63–66 HRC | 67–70 HRC |
| Density | 8.10 g/cm³ | 7.90 g/cm³ |
| Red hardness | High (8% cobalt) | Excellent — top of the conventional HSS range |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: M36 · M42. Substitution decisions for certified parts stay with the design authority.