Patent ID: 7621035

Claim:
A method of manufacturing a golf club head (a) having a lateral moment of inertia of not less than 3500 g cm 2 and a vertical moment of inertia of not less than 2000 g cm 2 , and (b) comprising (1) a face member for forming a face for hitting a golf ball, (2) a crown member for forming a crown, (3) a walled sole member for forming a sole and a sidewall extending from the periphery of the sole towards the crown excluding the face and (4) a neck member for forming a neck to be fixed to a shaft, the method comprising making the walled sole member and the entirety of the neck member integrally from a first titanium alloy by monoblock casting, so that the walled sole member has a maximum thickness (t 2 ) of at most 3.5 mm and a minimum thickness (t 1 ), and the ratio (t 2 /t 1 ) of the maximum thickness (t 2 ) to the minimum thickness (t 1 ) is in a range of from 1.5 to 2.5, wherein the monoblock casting is a lost-wax process, making the face member of a different metal material than the walled sole member by plastic deformation processing, wherein the plastic deformation processing is a press forming of a rolled sheet of the metal material, making the crown member having a thickness not more than 1.2 mm and thinner than the face member by press forming of a rolled sheet of a second titanium alloy whose tensile strength is higher than that of the first titanium alloy, and welding the face member, crown member and walled sole member together.