17-4 H900

17-4 H900 Stainless Steel is a martensitic stainless steel that is used in a wide range of applications due to its strong combination of high strength and excellent resistance to corrosion. Eight different heat treatments have been developed starting with H900 up to H1150-M. Specifications include but are not limited to AISI 630, AMS 2303, AMS 5643, ASTM, A370, ASTM A564 and ASTM F899.

Common Applications

Due to the material’s high strength and corrosion resistance 17-4 H900 is used in a wide range of applications:

• Oil & gas foils, helicopter deck platforms
• Chemical processing equipment
• Biomedical hand tools
• Aerospace structural parts
• Valve trim
• Various marine applications
• Pump shafts, gears, plungers
• Food production equipment

Medical Application Details

Due to the material’s high strength and strong corrosion resistance with an ASTM F899 specification, the grade is used in a wide range of surgical instruments. However, in contrast to other grades, 17-4 H900 is not an implantable metal. Instead, it is primarily used for various surgical instruments including but not limited to surgical scissors, ear pins, rollers and guides.

Material Characteristics 

17-4 H900 has excellent mechanical properties and is inexpensive relative to comparable high-nickel, non-ferrous alloys. It’s corrosion resistance is generally comparable to 304 and is better than the 400 series. Note that long-term exposure to elevated temperature can result in lower toughness. Severe cold working should be done primarily at the H1150 condition to avoid cracking.

Additional Information:

Martensitic Stainless Steel (17-4 PH Classification)

Stainless steels fall into four main categories: martensitic, austenitic, ferritic, and duplex. Martensitic stainless steels are defined by material that can be tempered and hardened by aging or heat treatment.

Martensitic material can be sub-divided into two categories:

1) High carbon material (above 0.4% carbon) used mainly for wear resistance (surgical instruments, molds, etc.)

2) Low carbon material (below 0.4% carbon) used mostly for their mechanical properties (shafts, valves, etc.)

Relative to other martensitic material, 17-4 has a low carbon content (<0.07%).