17-4PH Stainless Steel

17-4PH is a precipitation-hardening stainless steel combining high strength, high hardness, good corrosion resistance, and dimensional stability. “17-4” refers approximately to its 17% chromium and 4% nickel content, while PH stands for Precipitation Hardening. Different aging treatments can provide different combinations of strength, hardness, and toughness, making it well suited for highly loaded precision CNC components.

Appearance & Properties

Color: Silver-gray to bright silver

Density: Approx. 7.75–7.8 g/cm³

Tensile Strength: Approx. 930–1,310+ MPa (depending on heat treatment condition)

Corrosion Resistance: Good

Machinability: Moderate to good

Wear Resistance: Good

Weldability: Good

Magnetism: Magnetic

Heat Treatment: Strength and hardness can be adjusted through aging treatments

Surface Finishes: Passivation, polishing, grinding, bead blasting, etc.

Typical Applications

17-4PH Stainless Steel is widely used in aerospace, energy, oil and gas, marine, automotive, food equipment, and high-performance industrial machinery.

Typical parts include high-strength shafts, valve stems, valve components, pump parts, gears, fasteners, aerospace structural components, connectors, and high-load precision CNC parts.

Advantages

• High strength and hardness

• Good corrosion resistance

• Good dimensional stability after heat treatment

• Good balance of strength, toughness, and corrosion resistance

• Suitable for highly loaded precision mechanical components

Limitations

• More difficult to machine than free-machining grades such as 303 and 416

• Increased tool wear in high-hardness conditions

• Generally more expensive than common grades such as 304

• Lower corrosion resistance than 316L in highly aggressive environments