18CrNiMo7-6 vs 51CrMoV4: 28% composition overlap. Significantly different materials serving different application areas.
18CrNiMo7-6 vs 51CrMoV4
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.
51CrMoV4
1.7701
CrMoV alloyed spring steel — THE European automotive suspension spring material. CrMo gives deep hardenability for large coil springs, V adds grain refinement and secondary hardening for fatigue resistance. UTS 1350-1600 MPa QT. Used for hot-formed coil springs (cars, trucks), leaf springs, torsion bars, and stabilizer bars. Excellent sag resistance to 200°C.
| 18CrNiMo7-6 | 51CrMoV4 | |
|---|---|---|
| Material Number | 1.6587 | 1.7701 |
| Category | Alloy Steel | Alloy Steel |
| Standard | EN 10084 | EN 10089 |
Chemical composition (wt%)
| Element | 18CrNiMo7-6 | 51CrMoV4 | Overlap |
|---|---|---|---|
| C | 0.15–0.21% | 0.47–0.55% | No overlap |
| Si | 0–0.4% | 0–0.4% | OK |
| Mn | 0.5–0.9% | 0.7–1% | Partial |
| P | 0–0.025% | — | — |
Mechanical properties
| Property | 18CrNiMo7-6 | 51CrMoV4 | Unit |
|---|---|---|---|
| hardness_hrc | 58–62 | — | HRC |
| tensile_strength | 1050–1350 | 1350–1600 | MPa |
| hardness_hb | ≤ 229 | — | HB |
Compatibility Assessment
18CrNiMo7-6 and 51CrMoV4 have significantly different compositions (28% 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 51CrMoV4?
18CrNiMo7-6 and 51CrMoV4 have a 28% composition overlap. They are generally not directly interchangeable.
Can I replace 18CrNiMo7-6 with 51CrMoV4?
Generally not recommended. The compositions differ significantly (28% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 18CrNiMo7-6 and 51CrMoV4?
The main differences are in the following elements: C, Mn, Cr, Mo. 18CrNiMo7-6 is a Alloy Steel grade, while 51CrMoV4 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.