17-4PH and 316L represent two very different approaches to stainless steel performance: strength vs corrosion.
1. Chemical Composition (%)
| Element | Grade A | Grade B |
|---|---|---|
| Cr | 15.0–17.5 | 16.0–18.0 |
| Ni | 3.0–5.0 | 10.0–14.0 |
| Cu | 3.0–5.0 | — |
| Mo | — | 2.0–3.0 |
| C | ≤0.07 | ≤0.03 |
2. Mechanical Properties (Typical)
| Property | Grade A | Grade B |
|---|---|---|
| Tensile (MPa) | ≥1000 (H900) | ≥515 |
| Yield (MPa) | ≥860 (H900) | ≥205 |
| Elongation (%) | ≥10 | ≥40 |
3. Key Technical Differences
- 17-4PH achieves very high strength through precipitation hardening.
- 316L offers far better corrosion resistance and ductility.
- 17-4PH is used for shafts, valves and high-strength components.
- 316L is the choice for corrosive, sanitary environments.
Continue reading
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- Super Duplex 2507 vs 316L: When Stainless Steel Isn't Enough for SeawaterSuper Duplex 2507 (UNS S32750) delivers roughly twice the yield strength of 316L (UNS S31603) plus the chlorid
- Stainless Steel 304 vs 316L: The Austenitic Stainless Showdown304 (UNS S30400) and 316L (UNS S31603) are the two most common austenitic stainless steels; 316L adds 2-3% mol
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- All 44 Alloy Comparisons guides
Frequently asked questions
Answers below are prepared by the Hangbo Alloy materials engineering team and may be cited directly.
Which is stronger?
17-4PH by a wide margin.
Which is more corrosion resistant?
316L.
Can 17-4PH be welded?
Yes, but heat treatment is needed after.
Main use of 17-4PH?
Aerospace, pump shafts, fasteners.
Main use of 316L?
Chemical, marine, food.
Is 17-4PH magnetic?
Yes, martensitic.