18CrNiMo7-6 vs 34CrAlNi7: 8% composition overlap. Significantly different materials serving different application areas.
18CrNiMo7-6 vs 34CrAlNi7
Side-by-side chemical composition and mechanical property comparison.
Overview
18CrNiMo7-6
1.6587
Premium Cr-Ni-Mo case-hardening steel for the most demanding gear applications. Excellent core toughness and hardenability for large cross-sections. The standard gear steel for wind turbines, heavy-duty gearboxes, and aerospace gearing.
34CrAlNi7
1.8550
THE classic aluminum-containing nitriding steel — Al 0.8-1.2% forms extremely hard AlN nitrided layer (900-1100 HV surface). Cr 1.0-1.3% + Ni 0.85-1.15% provide core strength. Highest achievable surface hardness of all nitriding steels. Used for cylinder liners, piston rings, crankshafts, spindles, and gauges where maximum nitrided hardness is critical. Also known as 34CrAlNi7-10.
| 18CrNiMo7-6 | 34CrAlNi7 | |
|---|---|---|
| Material Number | 1.6587 | 1.8550 |
| Category | Alloy Steel | Alloy Steel |
| Standard | EN 10084 | EN 10085 |
Chemical composition (wt%)
| Element | 18CrNiMo7-6 | 34CrAlNi7 | Overlap |
|---|---|---|---|
| C | 0.15–0.21% | 0.3–0.37% | No overlap |
| Si | 0–0.4% | — | — |
| Mn | 0.5–0.9% | 0.4–0.7% | Partial |
| P | 0–0.025% | — | — |
Mechanical properties
| Property | 18CrNiMo7-6 | 34CrAlNi7 | Unit |
|---|---|---|---|
| hardness_hrc | 58–62 | — | HRC |
| tensile_strength | 1050–1350 | 830–1030 | MPa |
| hardness_hb | ≤ 229 | — | HB |
Compatibility Assessment
18CrNiMo7-6 and 34CrAlNi7 have significantly different compositions (8% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is 18CrNiMo7-6 the same as 34CrAlNi7?
18CrNiMo7-6 and 34CrAlNi7 have a 8% composition overlap. They are generally not directly interchangeable.
Can I replace 18CrNiMo7-6 with 34CrAlNi7?
Generally not recommended. The compositions differ significantly (8% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 18CrNiMo7-6 and 34CrAlNi7?
The main differences are in the following elements: C, Mn, Cr, Mo. 18CrNiMo7-6 is a Alloy Steel grade, while 34CrAlNi7 is a Alloy Steel grade.
View full data for each material:
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.