15-5PH / X5CrNiCuNb15-5 vs 17-4PH: Extremely similar PH stainless steels — 15-5PH has better transverse properties
15-5PH / X5CrNiCuNb15-5 vs 17-4PH
Side-by-side chemical composition and mechanical property comparison.
Overview
15-5PH / X5CrNiCuNb15-5
1.4545
Martensitic precipitation-hardening stainless steel. Similar to 17-4PH but with better transverse ductility and toughness due to lower delta ferrite. Used for aerospace structural components, nuclear reactor parts, food processing equipment, and high-performance fasteners.
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.
| 15-5PH / X5CrNiCuNb15-5 | 17-4PH | |
|---|---|---|
| Material Number | 1.4545 | 1.4542 |
| Category | Stainless Steel | Stainless Steel |
| Standard | AMS 5659 | EN 10088-3 |
Chemical composition (wt%)
| Element | 15-5PH / X5CrNiCuNb15-5 | 17-4PH | Overlap |
|---|---|---|---|
| C | 0–0.07% | 0–0.07% | OK |
| Si | 0–1% | 0–0.7% | OK |
| Mn | 0–1% | 0–1.5% | OK |
| P | 0–0.03% | 0–0.04% | OK |
Mechanical properties
| Property | 15-5PH / X5CrNiCuNb15-5 | 17-4PH | Unit |
|---|---|---|---|
| tensile_strength | ≥ 1310 | ≥ 1310 | MPa |
| yield_strength | ≥ 1170 | ≥ 1170 | MPa |
| elongation | ≥ 10 | ≥ 10 | % |
Compatibility Assessment
15-5PH has tighter composition control (lower delta ferrite) for superior transverse ductility and impact toughness. Essentially the same strength. Choose 15-5PH for aerospace where isotropic properties matter.
Frequently Asked Questions
Is 15-5PH / X5CrNiCuNb15-5 the same as 17-4PH?
15-5PH / X5CrNiCuNb15-5 and 17-4PH have a 90% composition overlap. Extremely similar PH stainless steels — 15-5PH has better transverse properties
Can I replace 15-5PH / X5CrNiCuNb15-5 with 17-4PH?
In many cases, yes. The compositions overlap significantly (90%). However, always verify mechanical property requirements and heat treatment compatibility for your specific application.
What is the difference between 15-5PH / X5CrNiCuNb15-5 and 17-4PH?
The main differences are in the following elements: Cr, Ni, Cu. 15-5PH / X5CrNiCuNb15-5 is a Stainless Steel grade, while 17-4PH is a Stainless Steel grade.
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Data provided for reference only. Always verify against the applicable specification for critical applications.
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