17-4 PH Stainless Steel Round Bars
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What Is 17-4 PH Stainless Steel Round Bar?
17-4 PH (UNS S17400 / EN 1.4542) is a precipitation-hardening martensitic stainless steel. In round bar form, it is especially suitable for CNC machining, shafts, pins, fasteners, and rotating components. Strength is developed through aging treatment rather than high carbon content, allowing excellent mechanical performance with controlled distortion.Compared with 304 or 316 round bars, 17-4 PH offers significantly higher yield strength while maintaining practical corrosion resistance.
What is the standards for 17-4 PH stainless steel bars?
The standards for 17-4 PH stainless steel bars are defined by key material specifications such as UNS S17400, AMS 5643, and ASTM A564 (Grade 630), which provide different mechanical properties (strength, hardness) depending on the heat treatment conditions (e.g., Solution Annealed, H900, H1150) to meet the requirements of applications demanding high strength and corrosion resistance.
17-4 PH Stainless Steel Round Bars Specifications
| Item | Details |
|---|---|
| Grade | 17-4 PH / UNS S17400 / EN 1.4542 |
| Standards | ASTM A564, ASTM A705, AMS 5643 |
| Diameter Range | 6 mm – 300 mm |
| Length | 3 m / 6 m / Cut-to-length |
| Supply Condition | Solution Annealed, H900, H1025, H1150 |
| Surface Finish | Hot rolled, Cold drawn, Peeled, Turned |
| Certification | EN 10204 3.1 / SGS / BV |
Chemical Composition of 17-4 PH Stainless Steel
| Element | Content (%) |
|---|---|
| Chromium (Cr) | 15.0 – 17.5 |
| Nickel (Ni) | 3.0 – 5.0 |
| Copper (Cu) | 3.0 – 5.0 |
| Niobium + Tantalum (Nb+Ta) | 0.15 – 0.45 |
| Carbon (C) | ≤ 0.07 |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 1.0 |
Mechanical Properties of 17-4 PH Round Bars
Mechanical properties vary depending on heat treatment, giving designers flexibility to balance strength and toughness.
| Condition | Tensile Strength (MPa) | Yield Strength (MPa) | Hardness |
|---|---|---|---|
| Solution Annealed | ≥ 930 | ≥ 725 | ≤ 35 HRC |
| H900 | ≥ 1310 | ≥ 1170 | 40–44 HRC |
| H1025 | ≥ 1070 | ≥ 1000 | 35–38 HRC |
| H1150 | ≥ 860 | ≥ 725 | 28–32 HRC |
Does 17-4 PH round bar resist corrosion?
Yes, 17-4 PH offers good corrosion resistance comparable to 304 in many environments (due to 17% Cr content), but it is less resistant to pitting and crevice corrosion than 316 stainless steel because it lacks molybdenum; PREN value is ~24–30, versus 316's ~24–26 (similar range but depends on heat treatment).
Which heat treatment is best for machining 17-4 PH round bars?
Solution annealing at 1040 °C followed by rapid cooling (water or air quenching) is recommended before machining, as this produces a soft, ductile structure (Condition H1150M or H1075) with Brinell hardness around 277 HB, reducing tool wear and improving machinability.
What is 17-4 PH stainless steel round bar used for?
17-4 PH stainless steel round bars are primarily used in aerospace components (landing gear, turbine shafts), nuclear reactor internals, surgical instruments, high-performance valves, and chemical processing equipment due to their combination of high strength, hardness, and corrosion resistance after aging.
Is 17-4 PH stronger than 304 or 316 stainless steel?
Yes, 17-4 PH is significantly stronger than both 304 and 316 stainless steels-after aging (H900 condition), it achieves ultimate tensile strength of approximately 1310 MPa and yield strength of 1170 MPa, compared to 304's ~515 MPa tensile and 316's ~485 MPa tensile at room temperature.
17-4 PH Stainless Steel Round Bar Prices (Latest as of 2026)
As of January 2026, the price of standard 17-4 PH (UNS S17400, SUS 630, EN 1.4542) stainless steel round bars is US$4.8-7.2 per kilogram (FOB Shanghai), conforming to ASTM A484/A276 standards. Specifically, 17-4 PH SS hot-rolled round bars (10-130 mm diameter, black/pickled surface) are priced at US$4.8-5.8 per kilogram, while 17-4 PH SS cold-drawn bright bars (3-60 mm diameter, polished surface, H9-H10 tolerance) are priced at US$5.5-7.2 per kilogram due to higher precision requirements. The pricing of this product primarily depends on its precipitation hardening composition (15.0-17.5% chromium, 3.0-5.0% nickel, 3.0-5.0% copper, 0.15-0.45% niobium).
GNEE is a reliable supplier of 17-4PH round bars, offering UNS S17400 / W.Nr. 1.4542 round bars with diameters typically ranging from Ø6 mm to Ø450 mm, available in solution annealed or solution annealed and aged conditions.
All 17-4PH stainless steel round bars are manufactured according to ASTM A276 and ASTM A479 standards and can be supplied with EN 10204 3.1 certificates.
GNEE offers various product forms, such as hot-rolled bars, forged bars, peeled bars, polished bars, and cut-to-length bars, to meet different processing and performance requirements.
For transportation and packaging, the round bars are protected with anti-rust oil, plastic wrapping, and packaged in seaworthy wooden crates or steel strapping.
