17-4PH vs X8CrNiS18-9: 33% composition overlap. Significantly different materials serving different application areas.
17-4PH vs X8CrNiS18-9
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.
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.
| 17-4PH | X8CrNiS18-9 | |
|---|---|---|
| Material Number | 1.4542 | 1.4305 |
| Category | Stainless Steel | Stainless Steel |
| Standard | EN 10088-3 | EN 10088-3 |
Chemical composition (wt%)
| Element | 17-4PH | X8CrNiS18-9 | Overlap |
|---|---|---|---|
| C | 0–0.07% | 0–0.1% | OK |
| Si | 0–0.7% | 0–1% | OK |
| Mn | 0–1.5% | 0–2% | OK |
| P | 0–0.04% | — | — |
Mechanical properties
| Property | 17-4PH | X8CrNiS18-9 | Unit |
|---|---|---|---|
| tensile_strength | ≥ 1310 | 500–750 | MPa |
| yield_strength | ≥ 1170 | ≥ 190 | MPa |
| elongation | ≥ 10 | ≥ 35 | % |
Compatibility Assessment
17-4PH and X8CrNiS18-9 have significantly different compositions (33% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is 17-4PH the same as X8CrNiS18-9?
17-4PH and X8CrNiS18-9 have a 33% composition overlap. They are generally not directly interchangeable.
Can I replace 17-4PH with X8CrNiS18-9?
Generally not recommended. The compositions differ significantly (33% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 17-4PH and X8CrNiS18-9?
The main differences are in the following elements: S, Cr, Ni, Cu. 17-4PH is a Stainless Steel grade, while X8CrNiS18-9 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.