15-5PH / X5CrNiCuNb15-5 vs X8CrNiS18-9: 31% composition overlap. Significantly different materials serving different application areas.
15-5PH / X5CrNiCuNb15-5 vs X8CrNiS18-9
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.
X8CrNiS18-9
1.4305
THE free-cutting austenitic stainless — AISI 303. Sulfur 0.15-0.35% for short-breaking chips and excellent machinability. Not weldable (hot cracking risk from S). Reduced corrosion resistance vs 304 due to sulfide inclusions. Used for high-volume CNC screw machine production of fittings, shafts, bushings, valves, and any turned stainless part where machining cost dominates.
| 15-5PH / X5CrNiCuNb15-5 | X8CrNiS18-9 | |
|---|---|---|
| Material Number | 1.4545 | 1.4305 |
| Category | Stainless Steel | Stainless Steel |
| Standard | AMS 5659 | EN 10088-3 |
Chemical composition (wt%) — Pro
| Element | 15-5PH / X5CrNiCuNb15-5 | X8CrNiS18-9 | Overlap |
|---|---|---|---|
| C | 0–0.07% | 0–0.1% | OK |
| Si | 0–1% | 0–1% | OK |
| Mn | 0–1% | 0–2% | OK |
| P | 0–0.03% | — | — |
| S | |||
| Cr | |||
| Ni | |||
| Cu | |||
| Nb |
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Sign up free — 3 comparisons/day freeMechanical properties — Pro
| Property | 15-5PH / X5CrNiCuNb15-5 | X8CrNiS18-9 | Unit |
|---|---|---|---|
| Tensile Strength | ≥ 1310 | 500–750 | MPa |
| Yield Strength | ≥ 1170 | ≥ 190 | MPa |
| Elongation | ≥ 10 | ≥ 35 | % |
| Hardness HRC | |||
| Elastic Modulus | |||
| Density | |||
| Hardness HB | |||
| Tensile Strength | |||
| Yield Strength Rp0.2 | |||
| Elongation A | |||
| Hardness HB |
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Sign up free — 3 comparisons/day freeCompatibility Assessment
15-5PH / X5CrNiCuNb15-5 and X8CrNiS18-9 have significantly different compositions (31% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is 15-5PH / X5CrNiCuNb15-5 the same as X8CrNiS18-9?
15-5PH / X5CrNiCuNb15-5 and X8CrNiS18-9 have a 31% composition overlap. They are generally not directly interchangeable.
Can I replace 15-5PH / X5CrNiCuNb15-5 with X8CrNiS18-9?
Generally not recommended. The compositions differ significantly (31% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 15-5PH / X5CrNiCuNb15-5 and X8CrNiS18-9?
The main differences are in the following elements: S, Cr, Ni, Cu. 15-5PH / X5CrNiCuNb15-5 is a Stainless Steel grade, while X8CrNiS18-9 is a Stainless 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.