30CrNiMo8 vs 34CrNiMo6
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.
30CrNiMo8
Alloy & Engineering Steel
30CrNiMo8 is a high-hardenability EN Q&T steel (1.6580) with about 2% each of chromium and nickel. It is specified for large, highly stressed parts — rotor shafts, aircraft components and heavy fasteners — where 42CrMo4 runs out of section capability.
Standards: DIN 1.6580 (30CrNiMo8)
34CrNiMo6
Alloy & Engineering Steel
34CrNiMo6 is the EN Ni-Cr-Mo Q&T steel (1.6582) for wind-energy shafts, large gears and heavy machinery. Its balanced 1.5% Cr/Ni package gives deep hardenability with good toughness at moderate alloy cost.
Standards: DIN 1.6582 (34CrNiMo6) · AISI 4337 (near)
Chemical composition compared (%)
| Element | 30CrNiMo8 | 34CrNiMo6 |
|---|---|---|
| C | 0.26–0.34 | 0.30–0.38 |
| Si | ≤0.40 | ≤0.40 |
| Mn | 0.50–0.80 | 0.50–0.80 |
| P | ≤0.025 | ≤0.025 |
| S | ≤0.035 | ≤0.035 |
| Cr | 1.80–2.20 | 1.30–1.70 |
| Ni | 1.80–2.20 | 1.30–1.70 |
| Mo | 0.30–0.50 | 0.15–0.30 |
Properties compared
| Property | 30CrNiMo8 | 34CrNiMo6 |
|---|---|---|
| Hardness (Q&T) | 34–44 HRC typical | 32–42 HRC typical |
| Tensile strength | 1100–1400 MPa (Q&T, EN 10083 section bands) | 1000–1300 MPa (Q&T, EN 10083 section bands) |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
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: 30CrNiMo8 · 34CrNiMo6. Substitution decisions for certified parts stay with the design authority.