34CrNiMo6 vs 40CrNiMo6: Same Cr-Ni-Mo family — 40CrNiMo6 is higher C for more strength
34CrNiMo6 vs 40CrNiMo6
Side-by-side chemical composition and mechanical property comparison.
Overview
34CrNiMo6
1.6582
High-strength quenched and tempered Cr-Ni-Mo steel. Excellent hardenability and toughness, suitable for large cross-sections. Used for heavy-duty shafts, gears, turbine parts, and aerospace components.
40CrNiMo6
1.6565
High-strength Cr-Ni-Mo quench and temper steel. Higher C than 34CrNiMo6 for greater strength, with excellent hardenability from Ni+Mo combination. Used for heavy-duty crankshafts, connecting rods, high-strength bolts (class 12.9), gears, and critical structural components in large cross-sections.
| 34CrNiMo6 | 40CrNiMo6 | |
|---|---|---|
| Material Number | 1.6582 | 1.6565 |
| Category | Alloy Steel | Alloy Steel |
| Standard | EN 10083-3 | EN 10083-3 |
Chemical composition (wt%) — Pro
| Element | 34CrNiMo6 | 40CrNiMo6 | Overlap |
|---|---|---|---|
| C | 0.3–0.38% | 0.36–0.44% | Partial |
| Si | 0–0.4% | 0–0.4% | OK |
| Mn | 0.5–0.8% | 0.5–0.8% | OK |
| P | 0–0.025% | 0–0.025% | OK |
| S | |||
| Cr | |||
| Mo | |||
| Ni |
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Sign up free — 3 comparisons/day freeMechanical properties — Pro
| Property | 34CrNiMo6 | 40CrNiMo6 | Unit |
|---|---|---|---|
| Tensile Strength | 1000–1200 | 1000–1200 | MPa |
| Yield Strength | ≥ 800 | ≥ 800 | MPa |
| Elongation | ≥ 11 | ≥ 10 | % |
| Hardness HRC | |||
| Elastic Modulus | |||
| Density |
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Sign up free — 3 comparisons/day freeCompatibility Assessment
40CrNiMo6 reaches 1000-1200 MPa UTS (vs 900-1100 for 34CrNiMo6). 34CrNiMo6 is tougher and more widely available. Choose 40CrNiMo6 for class 12.9 bolts and maximum strength; 34CrNiMo6 for general high-strength QT.
Frequently Asked Questions
Is 34CrNiMo6 the same as 40CrNiMo6?
34CrNiMo6 and 40CrNiMo6 have a 85% composition overlap. Same Cr-Ni-Mo family — 40CrNiMo6 is higher C for more strength
Can I replace 34CrNiMo6 with 40CrNiMo6?
In many cases, yes. The compositions overlap significantly (85%). However, always verify mechanical property requirements and heat treatment compatibility for your specific application.
What is the difference between 34CrNiMo6 and 40CrNiMo6?
The main differences are in the following elements: C, Cr. 34CrNiMo6 is a Alloy Steel grade, while 40CrNiMo6 is a Alloy Steel grade.
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Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.