17-7PH Precipitation-Hardening Stainless Steel Round Bar with High Strength and Hardness Excellent Fatigue Properties and Good Corrosion Resistance

• Premium semi-austenitic precipitation hardening stainless steel 17-7PH (UNS S17700, W.Nr 1.4568, SUS631)
• Aluminum precipitation strengthening delivers ultra-high tensile strength and outstanding fatigue resistance after aging treatment
• Excellent dimensional stability with minimal deformation during heat treatment process
• Corrosion performance comparable to 304 stainless steel, superior to ordinary martensitic PH steel
• Good formability under solution annealed Condition A state for complex precision machining
• Multiple aging heat treatment options (RH950, RH1050, CH900) to match different strength & toughness demands
• Manufactured fully compliant with ASTM A564, AMS 5644 international aerospace standards
• Long service life for high-load precision components, low maintenance cost

This series of 17-7PH round bars are hot forged & hot rolled solid semi-austenitic precipitation hardening stainless steel rods. After complete solution annealing, the material owns uniform internal grain structure, tight dimensional tolerance and great machinability. Custom aging heat treatment can be arranged to reach targeted high strength, hardness and fatigue performance.

17-7PH is aluminum-strengthened PH stainless steel, widely used in aerospace, precision spring and high-strength fastener fields. It balances superior formability before aging and ultra-high mechanical strength after aging, with less heat treatment distortion than other PH grades, ideal for intricate precision parts that need both rust resistance and extreme load capacity.

• Semi-austenitic precipitation hardening stainless steel containing Chromium, Nickel and Aluminum strengthening elements
• Forms fine aluminum precipitates during aging to sharply boost tensile strength, yield strength and fatigue resistance
• Low thermal deformation rate after heat treatment, perfect for complex thin-walled precision machined parts
• Moderate corrosion resistance matching grade 304, stable in atmospheric, fresh water and mild organic acid media
• Outstanding high-temperature spring performance, stable mechanical properties up to 316°C service temperature
• Available in various aging states to trade off hardness, ductility and impact toughness for diverse working conditions

Note: RH950/RH1050/CH900 custom aging treatment available for higher hardness & strength requirements.

• Precipitation Hardening Stainless Steel: 15-5PH, 17-4PH, PH13-8Mo, XM-12
• Austenitic stainless steel: 304,316L,310S,321,347,904L,254SMo,253Ma,A286(Gr.660)
• Duplex stainless steel: 2205,2507,S32750,S32760,F51,F55,F60
• Special nickel alloys: Monel 400/K-500, Inconel 600/625/718, Hastelloy C22/C276, Incoloy 800/825/925
• Alloy steel: 4140, 4340, F11, F22, F91,42CrMo
• Carbon steel:A105,A516 Gr.70,A36,S235JR,P235GH

1. Ultra-High Strength & Excellent Fatigue Resistance
   Aluminum precipitation hardening greatly improves tensile strength and fatigue performance, ideal for cyclic load components like springs, fasteners and transmission shafts.
2. Low Distortion After Heat Treatment
   Minimal dimensional change during aging, perfectly suited for intricate thin-walled precision parts with tight tolerance demands.
3. Balanced Corrosion Resistance
   Corrosion resistance equivalent to 304 stainless steel, far superior to common alloy steel and martensitic stainless steel in mild corrosive environments.
4. Good Formability & Machinability
   Soft solution annealed Condition A state supports turning, milling, stamping and complex forming before aging hardening process.
5. Stable High-Temperature Performance
   Retain reliable mechanical properties up to 316°C continuous working temperature, widely used for high-temperature spring and sealing components.

• Aerospace airframe fasteners, precision springs and aircraft structural components
• Aviation engine sealing parts, high-temperature washers and elastic components
• Precision instrument springs, electronic connectors and elastic hardware
• Chemical & food machinery high-strength bolts, valve core and wear-resistant sleeves
• Coastal marine corrosion resistant fasteners and small structural blanks
• Medical precision equipment, hydraulic actuator and load-bearing parts
• Automotive high-performance springs and exhaust system fittings

We provide integrated hot forging, hot rolling and full precision machining services, and can produce finished components strictly according to customer drawings:

• Cutting to fixed length, peeling, surface grinding & polishing
• CNC Turning, Milling, Planing, Drilling, Boring, Threading
• Custom aging heat treatment: RH950 / RH1050 / CH900
• Gear cutting, special profile forming and surface passivation treatment

We have supplied a wide range of machined parts including shafts, spring blanks, fasteners, valve sleeves and precision hardware to customers worldwide.

• Ultrasonic testing (UT) for internal rolling & forging defects
• Tensile testing machine & hardness tester for mechanical property verification
• High-precision dimensional measuring instrument for tolerance inspection
• Spectrometer for full chemical composition verification per batch
• Metallographic microscope for internal grain structure inspection

Mill Test Certificate (MTC EN 10204 3.1) can be provided together with shipment documents before delivery.

• Inner packaging: waterproof anti-rust polybag for moisture and dust protection
• Outer packaging: reinforced fumigated wooden case / wooden pallet, suitable for long-distance sea transportation
• Custom special packing solutions available upon customer request

Normally 10 – 45 days after receipt of advance payment. Exact delivery time depends on order quantity, bar diameter, length and customized heat treatment & machining requirements.

Please send us your required bar diameter, length, target aging condition, machining drawing and order quantity. Our professional engineer team will reply competitive factory direct price within 24 hours. Free material selection consultation and technical support for all clients!