17-4PH
Data verified17-4PH (type 630) is the most widely used precipitation-hardening stainless steel, combining near-316 corrosion resistance with strength levels up to about 1300 MPa after a simple low-temperature age. It hardens with minimal distortion, so parts are machined soft and aged to final strength.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.07 |
| Si | ≤1.00 |
| Mn | ≤1.00 |
| P | ≤0.040 |
| S | ≤0.030 |
| Cr | 15.00–17.50 |
| Ni | 3.00–5.00 |
| Cu | 3.00–5.00 |
| Nb | 0.15–0.45 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Solution treated (Condition A) or aged |
| Hardness (H900 aged) | ~40 HRC |
| Tensile strength (H900) | ~1310 MPa |
| Yield strength (H900) | ~1170 MPa |
| Density | 7.80 g/cm³ |
| Magnetic | Yes |
Heat treatment
Solution treat 1025–1055 °C, air cool (soft, Condition A); age to harden — H900: 482 °C/1 h (~1310 MPa), H1150: 621 °C/4 h (~930 MPa, best toughness and SCC resistance).
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.4542 |
| aisi | 630 (17-4PH) |
| jis | SUS630 |
| gb | 05Cr17Ni4Cu4Nb |
Compare side by side: 17-4PH vs 15-5PH · 17-4PH vs 17-7PH
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Aerospace fittings, pump shafts, valve stems, gears, fasteners, firearm and medical components.
Processing: Machines well in Condition A; welding is practical with post-weld solution-plus-age for full properties; ageing causes a small, predictable dimensional contraction.
FAQ
- Which 17-4PH condition should I buy?
- H1150 (or H1150M) for welded or sour-service parts needing toughness and stress-corrosion resistance; H900 only where maximum strength is essential and the environment is mild.
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Ask for a quotationVisit NasteelSource: ASTM A564 / EN 10088 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.