A nickel-cobalt based superalloy composition consisting of by weight (wt.): 33.5 to 54 percent Ni; 19.5 to 36 percent Co; 9 to 12 percent Cr; 3.9 to 5.5 percent Al; 4.5 to 9.5 percent W; up to 5.5 percent Fe; 2 to 3.5 percent Mo; 0.6 to 5 percent Ta; 0.15 to 2.2 percent Ti; up to 1.75 percent Nb; up to 0.1 percent Hf; 0.005 to 0.03 percent C; 0.001 to 0.02 percent B; 0.005 to 0.06 percent Zr; up to 0.3 percent Si; up to 0.6 percent Mn; and the balance being impurities.