PURPOSE: To provide a Co-Cr-W-C alloy having high temp. strength and toughness so that it can be utilized for a weld line.

CONSTITUTION: This is a carbide precipitation hardening type Co alloy having chemical components of, by weight, 26 to 35% Cr, 3 to 12% W and 0.9 to 3% C, and in which Mn is contained by ≥5 to S in a ratio of Mn/S, and the size (y) of carbides lies in the relationship of y≤-3x+11 to the amt. (x) of C. Moreover, in the crystalline structure, fcc is regulated to ≥20% (hcp is regulated to <80%), the length is regulated to ≥1000 times to the diameter, the deviation in diameter is regulated to ≤1/20, and its size is substantially same as that in a longitudinal direction.