42CrMo4 vs C45: Not equivalent — different steel classes
42CrMo4 vs C45
Side-by-side chemical composition and mechanical property comparison.
Overview
42CrMo4
1.7225
High-strength quenched and tempered chromium-molybdenum steel. Widely used for shafts, gears, crankshafts, connecting rods, and high-strength bolts. Excellent hardenability and good fatigue resistance.
C45
1.0503
Medium carbon unalloyed quality steel. Good machinability and moderate strength after heat treatment. Widely used for shafts, spindles, pins, studs, and general machine parts.
| 42CrMo4 | C45 | |
|---|---|---|
| Material Number | 1.7225 | 1.0503 |
| Category | Alloy Steel | Carbon Steel |
| Standard | EN 10083-3 | EN 10083-2 |
Chemical composition (wt%)
| Element | 42CrMo4 | C45 | Overlap |
|---|---|---|---|
| C | 0.38–0.45% | 0.42–0.5% | Partial |
| Si | 0–0.4% | 0–0.4% | OK |
| Mn | 0.6–0.9% | 0.5–0.8% | Partial |
| P | 0–0.025% | 0–0.03% | OK |
Mechanical properties
| Property | 42CrMo4 | C45 | Unit |
|---|---|---|---|
| tensile_strength | 900–1100 | 630–780 | MPa |
| yield_strength | ≥ 650 | ≥ 370 | MPa |
| elongation | ≥ 12 | ≥ 16 | % |
Compatibility Assessment
42CrMo4 is a Cr-Mo alloy steel with significantly higher strength and hardenability than C45. C45 is an unalloyed carbon steel. They should not be used interchangeably.
Frequently Asked Questions
Is 42CrMo4 the same as C45?
42CrMo4 and C45 have a 45% composition overlap. Not equivalent — different steel classes
Can I replace 42CrMo4 with C45?
Generally not recommended. The compositions differ significantly (45% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 42CrMo4 and C45?
The main differences are in the following elements: C, Mn, Cr, Mo. 42CrMo4 is a Alloy Steel grade, while C45 is a Carbon Steel grade.
Related Comparisons
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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.