ER630 (17-4 PH) is a martensitic precipitation, age-hardening 17% chromium -4% nickel stainless steel designed for welding ASTM A564 Type 630 and other martensitic PH stainless steels such as 15-5. Weld deposits have excellent mechanical properties with high strength and hardness. ER630 (17-4 PH) can be used with all welding processes without preheating, however post-weld heat treatment is recommended to produce weld properties comparable to the base metal. Commonly used in high temperature and abrasion resistant environments such as found in the petrochemical and aerospace industries.