17-4 PH Steel contains 4% copper and may be hardened by a single low temperature precipitation hardening heat treatment, producing excellent mechanical properties at a high strength level. 17-4 PH provides this high strength in combination with good mechanical properties at temperatures of up to 600°F (316°C).

17-4PH is readily hot forged. During heat treatment or forging, protective atmospheres containing carbon or nitrogen should be avoided. These elements can be absorbed into the steel surface and give soft austenitic skin. If a protective atmosphere is required argon or helium is recommended. The alloy also possesses good toughness when welded, while short low-temperature heat treatments reduce warping and scaling. Additionally, 17-4PH is easy to machine and fabricate.

Thanks to the beneficial properties, 17-4PH finds use in various industries. Typical parts include mechanical seals, oil patch, and pump shafts.