About 625|Inconel 625 (61% nickel, 21.5% chromium, 9% molybdenum, 3.6% niobium). The premium corrosion-resistant superalloy. Outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking in aggressive environments. Maintains strength to 1800°F. Machines terribly, among the worst materials a shop will encounter. Ceramic inserts at low speed or sharp, coated carbide at very low SFM with aggressive feeds. Rigid machine, rigid setup, flood coolant. Tool life is measured in minutes, not hours. Used for chemical processing, marine exhaust systems, and nuclear applications. Extremely expensive. Compare to 316 stainless (adequate for mild environments, 10x easier to machine) and
C276 (even better corrosion resistance).