What are the mainstream commercial grades of PH stainless steel?

The most widely used grades cover 17-4PH, 15-5PH and 17-7PH with different element ratios for differentiated working demands. 17-4PH owns balanced strength and corrosion resistance for general high-strength anti-corrosion components. 15-5PH features finer grain structure and better transverse toughness to reduce crack risks under cyclic loads. 17-7PH provides ultra-high strength after aging and is suitable for thin elastic precision parts. Each grade matches unique solution and aging temperature procedures to stabilize precipitated strengthening phases inside the metal matrix.