PH Stainless Steel Supplier, PH stainless steels (precipitation-hardening) contain around 17% chromium and 4% nickel. The precipitation hardening (PH) stainless steels are a family of corrosion resistant alloys some of which can be heat treated to provide tensile strengths of 850MPa to 1700MPa and yield strengths of 520MPA to over 1500MPa - some three or four times that of an austenitic stainless steel such as type 304 or type 316.