Patent ID: 6520868
Filing Date: 2003-02-18
Classification: A63B,C21D,C22C

Abstract:
A golf club head having a head shell, a face of said head shell and a neck for securing a shaft thereto,at least one of which is made of a steel alloy, the constituents of said steel alloy comprising maximum amounts of 0.03% of C by weight, 0.2Ëœ0.6% of Si by weight, maximum amounts of 0.15% of Mn by weight, maximum amounts of 0.03% of P by weight, maximum amounts of 0.03% of S by weight, 10.5Ëœ13.5% of Cr by weight, 0.8-1.4% of Mo by weight, 0.8-1.4% of Al by weight, 0.8Ëœ1.4% of Ni by weight, 0.02Ëœ0.1% of Nb by weight, maximum amounts of 0.01% of N by weight, maximum amounts of 0.03% of Cu by weight, and the rest being Fe; said steel alloy being made by a metallurgical method involving a vacuum melting process, and a normalizing process at a predetermined temperature and a predetermined time, whereby the main crystal structure of said steel alloy is ferrite.