17-7PH Stainless Steel

17-7 PH is a semi-austenitic precipitation hardening stainless steel that develops high strength and hardness through heat treatment. Conforming to AMS 5528 and AMS 5529, it is well suited to components requiring good formability in the annealed condition with minimum distortion during hardening.

Its aluminium content (0.75-1.50%) promotes the formation of a strengthening phase during aging. This gives 17-7 PH tensile strength between 1241 MPa and 1448 MPa in the hardened condition, placing it among the strongest sheet-form stainless steels available.

17-7 PH is particularly valued for flat spring applications operating up to 315°C, where its combination of high strength, good fatigue resistance, and corrosion resistance makes it the preferred choice. The aerospace industry, diaphragm and bellows manufacturers, and producers of precision formed parts also benefit from its ability to be formed in the soft condition before hardening to final properties.

The material is available in sheet and strip, making it practical for components produced by forming, stamping, or roll forming prior to heat treatment.