17-4PH / S17400 Stainless Steel Round Bar – Properties, Applications & Suppliers
17-4PH / S17400 Stainless Steel Round At Nifty Alloys, we are a trusted 17-4PH stainless steel round bar supplier in UAE, catering to aerospace, marine, petrochemical, and defense industries with certified and high-quality materials.– Properties, Applications & Suppliers
In industries where strength, toughness, and corrosion resistance are non-negotiable, 17-4PH Stainless Steel (UNS S17400 / WNR 1.4542) is one of the most relied-upon materials. Known as 17-4 Precipitation Hardening Stainless Steel, this versatile alloy combines the mechanical properties of high-strength steels with the corrosion resistance of stainless steels.
What is 17-4PH / S17400 Stainless Steel?
17-4PH stainless steel is a martensitic precipitation hardening (PH) stainless steel containing chromium, nickel, copper, and niobium. It was developed to offer superior strength with moderate corrosion resistance while being heat-treatable to different hardness levels.
It is widely known by:
- UNS S17400
- WNR 1.4542
- ASTM A564 Type 630
- Trade names: 17-4PH, Type 630, Grade 630
Key Features of 17-4PH Stainless Steel Round Bar
- High strength-to-weight ratio
- Excellent corrosion resistance, comparable to 304 stainless steel in many environments
- Magnetic in all heat treatment conditions
- Heat treatable: Can achieve different hardness levels by aging at H900, H1025, H1150, etc.
- Good machinability and weldability compared to conventional martensitic steels
Chemical Composition of 17-4PH
| Element | Content (%) |
|---|---|
| Chromium (Cr) | 15.0 – 17.5 |
| Nickel (Ni) | 3.0 – 5.0 |
| Copper (Cu) | 3.0 – 5.0 |
| Niobium (Nb) + Tantalum (Ta) | 0.15 – 0.45 |
| Carbon (C) | ≤ 0.07 |
| Manganese (Mn) | ≤ 1.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.04 |
| Sulfur (S) | ≤ 0.03 |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 1310 MPa |
| Yield Strength (0.2% Offset) | 1170 MPa |
| Elongation | 10 – 12% |
| Hardness | 44 HRC |
Note: Mechanical properties vary depending on heat treatment (H900, H1025, H1150, etc.).
Heat Treatment Conditions of 17-4PH Stainless Steel
The alloy can be supplied in different conditions, which allows engineers to balance strength and toughness as per requirements.
| Condition | Aging Temp (°C) | Tensile Strength (MPa) | Hardness (HRC) |
|---|---|---|---|
| H900 | 482 | ~1310 | 44 |
| H1025 | 552 | ~1170 | 38 |
| H1075 | 579 | ~1070 | 35 |
| H1150 | 621 | ~1000 | 28–32 |
Applications of 17-4PH Stainless Steel Round Bar
Because of its strength, toughness, and corrosion resistance, 17-4PH round bars are widely used in:
- Aerospace industry: turbine blades, shafts, fasteners, landing gear components
- Oil & Gas sector: pump shafts, valves, drilling equipment, pressure vessels
- Marine industry: propeller shafts, offshore platforms, naval equipment
- Defense & Military: firearm parts, structural components, missile systems
- Petrochemical & Power Plants: heat exchangers, reactor vessels, high-pressure equipment
- Food Processing: machinery parts that require strength and corrosion resistance
Equivalent Grades of 17-4PH Stainless Steel
| Standard | Grade |
|---|---|
| UNS | S17400 |
| WNR | 1.4542 |
| ASTM | A564 / A693 Type 630 |
| AMS | 5643, 5825 |
| AFNOR | Z6CNU17-04 |
| JIS | SUS 630 |
17-4PH vs. 15-5PH Stainless Steel – Key Differences
Both 17-4PH and 15-5PH are popular precipitation hardening stainless steels.
| Property | 17-4PH (S17400) | 15-5PH (S15500) |
|---|---|---|
| Corrosion Resistance | Good | Slightly better due to refined composition |
| Toughness | High | Higher, especially in thicker sections |
| Weldability | Good | Superior to 17-4PH |
| Applications | Aerospace, Marine, Oil & Gas | Aerospace, Nuclear, Chemical Processing |
Machining and Fabrication Guidelines
- Machinability: Comparable to martensitic steels; best results in H1150 condition.
- Welding: Can be welded by standard methods (TIG, MIG, SMAW). Post-weld heat treatment is recommended.
- Formability: Limited compared to austenitic steels like 304 or 316 stainless steel.
- Heat Treatment: Solution treatment at 1040 °C followed by aging at required condition (H900–H1150).
Why Choose Nifty Alloys for 17-4PH Round Bars?
- Leading stainless steel supplier in UAE & Middle East
- Wide stock range: round bars, plates, sheets, and forgings
- Cut-to-size services for project requirements
- Mill Test Certificates (MTCs) for complete traceability
- Competitive prices & fast delivery
Explore our alloy steels:
Conclusion
17-4PH / S17400 stainless steel round bar is a versatile and high-performance alloy that combines strength, corrosion resistance, and toughness. Its wide usage in aerospace, marine, oil & gas, and defense sectors makes it one of the most demanded stainless steels worldwide.
At Nifty Alloys, we stock and supply premium quality 17-4PH stainless steel bars in various diameters, ensuring fast delivery, competitive pricing, and complete certification.
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