304L vs 630 / 17-4PH: 54% composition overlap. Moderate differences, generally not direct substitutes.
304L vs 630 / 17-4PH
Side-by-side chemical composition and mechanical property comparison.
Overview
304L
1.4307
Low-carbon version of 304. Maximum 0.030% C prevents sensitization during welding — no post-weld heat treatment needed. The standard choice for welded structures in food, chemical, and pharmaceutical industries. Often dual-certified with 1.4301.
630 / 17-4PH
1.4542
Precipitation-hardening martensitic stainless steel — the highest-strength stainless in common use. Solution anneal at 1040°C then age at 480-620°C for UTS >1300 MPa. Corrosion resistance similar to 304. Cu+Nb precipitation hardening. Trade names include 17-4PH, SUS630. Used for aerospace structural parts, turbine blades, valve components, nuclear waste casks, medical instruments, and oil/gas equipment.
| 304L | 630 / 17-4PH | |
|---|---|---|
| Material Number | 1.4307 | 1.4542 |
| Category | Stainless Steel | Stainless Steel |
| Standard | EN 10088-2 | EN 10088-3 |
Chemical composition (wt%)
| Element | 304L | 630 / 17-4PH | Overlap |
|---|---|---|---|
| C | 0–0.03% | 0–0.07% | OK |
| Si | 0–1% | 0–0.7% | OK |
| Mn | 0–2% | 0–1.5% | OK |
| P | 0–0.045% | 0–0.04% | OK |
Mechanical properties
| Property | 304L | 630 / 17-4PH | Unit |
|---|---|---|---|
| tensile_strength | 500–700 | ≥ 1310 | MPa |
| yield_strength | ≥ 200 | ≥ 1170 | MPa |
| elongation | ≥ 45 | ≥ 10 | % |
Compatibility Assessment
304L and 630 / 17-4PH have moderate differences (54% overlap). They are generally not direct substitutes. Consider the specific requirements of your application.
Automated assessment based on composition analysis
Frequently Asked Questions
Is 304L the same as 630 / 17-4PH?
304L and 630 / 17-4PH have a 54% composition overlap. They are generally not directly interchangeable.
Can I replace 304L with 630 / 17-4PH?
Generally not recommended. The compositions differ significantly (54% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 304L and 630 / 17-4PH?
The main differences are in the following elements: Cr, Ni. 304L is a Stainless Steel grade, while 630 / 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.
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.