M50 vs M1
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.
M50
Tool Steel
M50 is a molybdenum high-speed steel developed for rolling bearings in jet engines, where it keeps hardness and fatigue life at operating temperatures near 300 °C. It is also used for high-performance cutting tools.
Standards: AISI M50
M1
Tool Steel
M1 is a molybdenum high-speed steel with the tungsten mostly replaced by about 8.7% molybdenum, making it tougher than T1 at equal hardness. It was developed for drills and taps where T-series steels chipped.
Standards: DIN — (HS9-2-1 family) · AISI M1 · JIS SKH55 (near) · GB W2Mo9Cr4V (near)
Chemical composition compared (%)
| Element | M50 | M1 |
|---|---|---|
| C | 0.77–0.85 | 0.78–0.88 |
| Si | ≤0.60 | ≤0.50 |
| Mn | ≤0.45 | ≤0.40 |
| Cr | 3.75–4.50 | 3.50–4.00 |
| Mo | 4.00–4.75 | 8.20–9.20 |
| V | 0.80–1.25 | 1.00–1.35 |
| W | — | 1.40–2.10 |
Properties compared
| Property | M50 | M1 |
|---|---|---|
| Delivery condition | Annealed | Annealed |
| Hardness (hardened) | 61–64 HRC | 62–65 HRC |
| Density | 7.90 g/cm³ | 7.90 g/cm³ |
| Fatigue performance | High — bearing-grade cleanliness specified | — |
| Red hardness | — | Good |
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: M50 · M1. Substitution decisions for certified parts stay with the design authority.