Stainless Steel
Stainless Steel 17-4PH (UNS S17400) — Composition, Properties & Supply
17-4PH (UNS S17400) is a martensitic precipitation-hardening stainless strengthened by copper. Machined in the solution-annealed state and given a single low-temperature age (H900–H1150), it reaches 930–1310 MPa tensile and HRC 30–45, balancing strength with corrosion resistance.
What is the chemical composition of Stainless Steel 17-4PH?
| Element | Symbol | Content (wt%) |
|---|---|---|
| Fe | Fe | Balance |
| Cr | Cr | 15.0–17.5 |
| Ni | Ni | 3.00–5.00 |
| Cu | Cu | 3.00–5.00 |
| Nb+Ta | Nb+Ta | 0.15–0.45 |
| Mn | Mn | ≤ 1.00 |
| Si | Si | ≤ 1.00 |
| C | C | ≤ 0.070 |
Values are typical specification limits. Actual heat analysis is reported on the EN 10204 3.1 mill test certificate supplied with each shipment.
What are the mechanical properties of Stainless Steel 17-4PH?
| Property | Value | Note |
|---|---|---|
| Tensile strength | ≥ 1310 MPa（H900） | Room temperature |
| Yield strength (0.2% offset) | ≥ 1170 MPa（H900） | Room temperature |
| Elongation | ≥ 10 % | Gauge length 50 mm / 4D |
| Hardness | ≥ 40 HRC | Brinell / Rockwell |
What are the physical properties of Stainless Steel 17-4PH?
| Property | Value |
|---|---|
| Density | 7.80 g/cm³ |
| Melting range | 1404–1440 °C |
| Thermal conductivity | 17.9 W/m·K |
| Elastic modulus | 196 GPa |
| Maximum service temperature | 300 °C (caution above H900) |
What are the key characteristics of Stainless Steel 17-4PH?
- Aged tensile up to 1310 MPa with hardness above HRC 40
- Simple heat treatment — a single low-temperature age with minimal distortion
- Corrosion resistance close to 304
- Ageing temperature tunes the strength/toughness balance
Where is Stainless Steel 17-4PH used?
- Aerospace structures and engine parts
- Valves, pump shafts and fasteners
- Oilfield machinery and downhole tools
- Moulds and extruder screws
- Medical and surgical instruments
Which standards and specifications cover Stainless Steel 17-4PH?
- ASTM A564
- ASTM A693
- AMS 5604
- UNS S17400
What product forms are available?
Frequently asked questions
Should I choose 17-4PH in H900 or H1150 condition?
H900 (482 °C for 1 h) gives maximum strength (tensile ≥ 1310 MPa, HRC 40+) but the lowest toughness and higher stress-corrosion susceptibility. H1150 (621 °C for 4 h) is weaker (about 1000 MPa tensile, HRC 31) but has the best toughness and SCC resistance. In chloride or sulphide service prefer H1100 or H1150.
Need Stainless Steel 17-4PH bar, tube, plate or forgings?
Send the grade, dimensions, standard and quantity. We answer within 10 minutes on working days and quote within 24 hours, with EN 10204 3.1 certification.
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