A metal alloy applied to manufacture a club weight member of a golf club head includes carbon less than 0.08% by weight, silicon of about 0.5% to about 2.0% by weight, manganese of about 0.5% to about 2.0% by weight, nickel of about 5.0% to about 15.0% by weight, chromium of about 15.0% to about 30.0% by weight, tungsten of about 5.0% to about 15.0% by weight and the balance is essential iron. Accordingly, the metal alloy has a high degree of mechanical strength and extensibility, and functions as a weight material of the golf club head.