17-4PH vs 440C / X105CrMo17: 75% composition overlap. Some similarities but notable differences in alloying elements.
17-4PH vs 440C / X105CrMo17
Side-by-side chemical composition and mechanical property comparison.
Overview
17-4PH
1.4542
The most widely used precipitation-hardening stainless steel. Combines high strength (up to 1310 MPa UTS) with corrosion resistance comparable to 304. Delivered solution-annealed and hardened by simple low-temperature aging. Used in aerospace, medical, oil & gas, and nuclear applications.
440C / X105CrMo17
1.4125
Highest-hardness standard martensitic stainless steel. Achieves 57-60 HRC — the hardest commonly available stainless grade. Excellent wear resistance from chromium carbides. Used for bearings, races, valve components, surgical instruments, high-end cutlery, and precision molds.
| 17-4PH | 440C / X105CrMo17 | |
|---|---|---|
| Material Number | 1.4542 | 1.4125 |
| Category | Stainless Steel | Stainless Steel |
| Standard | EN 10088-3 | EN 10088-3 |
Chemical composition (wt%)
| Element | 17-4PH | 440C / X105CrMo17 | Overlap |
|---|---|---|---|
| C | 0–0.07% | 0.95–1.2% | No overlap |
| Si | 0–0.7% | 0–1% | OK |
| Mn | 0–1.5% | 0–1% | OK |
| P | 0–0.04% | 0–0.04% | OK |
Mechanical properties
| Property | 17-4PH | 440C / X105CrMo17 | Unit |
|---|---|---|---|
| tensile_strength | ≥ 1310 | ≥ 690 | MPa |
| yield_strength | ≥ 1170 | ≥ 440 | MPa |
| elongation | ≥ 10 | — | % |
Compatibility Assessment
17-4PH and 440C / X105CrMo17 share some characteristics (75% overlap) but have notable differences. They may be substitutable in some applications but not all. Verify suitability carefully.
Automated assessment based on composition analysis
Frequently Asked Questions
Is 17-4PH the same as 440C / X105CrMo17?
17-4PH and 440C / X105CrMo17 have a 75% composition overlap. For most purposes, they can be considered similar.
Can I replace 17-4PH with 440C / X105CrMo17?
In many cases, yes. The compositions overlap significantly (75%). However, always verify mechanical property requirements and heat treatment compatibility for your specific application.
What is the difference between 17-4PH and 440C / X105CrMo17?
The main differences are in the following elements: C, Cr. 17-4PH is a Stainless Steel grade, while 440C / X105CrMo17 is a Stainless 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.