Abstract: A low carbon Martensite transformation induced substructure, with nickel and molybdenum providing solid solution strengthening is obtained in a low chromium-nickel casting steel consisting of less than 0.06 percent C, 4.75 to 5.75 percent Cr, 2.75 to 3.50 percent Ni, 0.45 to 0.65 percent Mo, less than 1.0 percent Mn, less than 0.75 percent Si, 0.05 to 0.12 percent Al, and less than 0.04 percent of each P and S with the remainder essentially Fe with a specific double normalize heat treat and temper in conjunction with controlled chemistry, the resulting material has excellent impact properties. The weldability and foundry handling characteristics are excellent without preheat. It has superior tensile properties and significantly higher impact properties than the present ASTM A 217 Gr. C5 alloy which it can replace. In addition, it can replace several of the alloys in ASTM A 352.