17-4 Stainless Steel


17-4 Stainless Steel (coming from the chemical makeup 17% chromium and 4% copper or UNS 17400) is a martensitic stainless grade that can be precipitation hardened through aging/heat treatment. 17-4 stainless steel, otherwise known as SAE Type 630 is frequently used with operations demanding high tensile strength and a middling level of corrosion resistance. 17-4 PH is the most used grade of martensitic precipitation hardenable alloys. 17-4 stainless steel is regarded as the most broadly formed precipitation hardening grade. Its intense tensile strength keeps its ductility and hardness at temperatures at nearly 600°F, while still demonstrating exceptional corrosion resistance in all conditions offered by Premium Alloys. Just as all martensitic metals, 17-4 is magnetic.


17-4 stainless steel can reach large levels of hardness, durability, and strength through heat treatment. 17-4 PH resists corrosion superior to any of the basic stainless steels that can be hardened. It is resistant to industries where the steel may be exposed to petroleum and most foods. Exceptional resistance to decay at roughly 1100°F. 17-4 stainless steel PH demonstrates great machinability.


Superior hardness can be obtained from welding after heat treatment. Machining conditions differ with firmness of the element. Different levels of strength and hardness can be achieved depending on the temperature it is heat treated at. The ASTM designation is A564 and common conditions are H900, H1025, H1075, H1150, and H1150D.

Physical Properties

Tensile Yield Enlongation Reduction
of Area
H900 190 170 10 40 40-47 HRC
H1025 150 145 12 45 35-42 HRC
H1075 145 125 13 45 33-39 HRC
H1150 135 105 16 50 28-37 HRC
H1150D 125 105 16 50 26-33 HRC


  • Oil and Gas
  • Pump and Boat Shaft
  • Seals
  • Valves
  • Petrochemical
  • Aerospace
  • Food Processing
  • Paper / Pulp
  • Jobs requiring hardness and corrosion resistance at temperatures below 600°F


  • Can be hardened to customize strength and hardness depending on the application
  • High strength with moderate corrosion resistance
  • Can be machined in solution treated and heat-treated conditions
  • Retains its mechanical properties and corrosion resistance up to roughly ~600°F
  • Great formability and weldability
  • Withstands corrosive attack better than any of the standard hardenable (martensitic) stainless steels
  • Superior resistance to corrosive material and high mechanical properties. This allows it to be used in marine environments.
  • Can be designed in such a way to seal radioactive storage.