The most widely used precipitation hardening grade steel, 17-4 stainless steel or SAE Type 630, is primarily composed of iron, chromium, nickel, and copper with trace amounts of other elements. It is known for its excellent mechanical properties, corrosion resistance, and ability to tolerate high temperatures. Classified under the martensitic family of stainless steel, the physical properties can be manipulated for specific applications depending on whether it has been annealed, hardened at 900° or at 1150°, and is magnetic depending on the heat treatment.
17-4 stainless steel’s high strength, corrosion resistance, and biocompatibility make it a common alloy used in medical applications, marine environments, chemical processing equipment, nuclear reactors, radioactive storage, and aerospace components. Its an ideal alloy for extreme environments with superior formability and weldability compared to other stainless steel grades.
| Property | Value | Notes |
|---|---|---|
| Material Type | Precipitation-Hardening Stainless Steel | Also known as UNS S17400 or Type 630 |
| Density | 7.75 g/cm³ | 0.280 lb/in³ |
| Melting Point | ~1,400–1,440°C | ~2,550–2,625°F |
| Hardness (HRC) | 28–44 | Depends on heat treatment (e.g., H900, H1150) |
| Tensile Strength | 1,070–1,400 MPa | ~155,000–200,000 psi, varies by condition |
| Yield Strength | 965–1,310 MPa | ~140,000–190,000 psi, varies by condition |
| Elongation at Break | 10–17% | Lower elongation than austenitic stainless steels |
| Modulus of Elasticity | ~200 GPa | ~29 x 10⁶ psi |
| Corrosion Resistance | High | Similar to 304 in many environments |
| Magnetism | Magnetic | Unlike most other stainless steels |
| Heat Treatment | Yes | Conditioned via aging: H900, H1025, H1150, etc. |
| Machinability | Moderate | Better in annealed state |
| Weldability | Fair to Good | Welded condition usually requires post-weld heat treatment |
With decades of experience and strong mill relationships, we’re more than just a distributor—we’re your trusted partner. Let us help you find what others can’t.
