US Patent 8047931 Golf club head

A golf club head comprises a face portion improved in the durability by increasing the strength of the toe-side upper region of the face portion. The face portion is formed from a unidirectionally rolled plate of a titanium alloy having alpha phase, and at least in the toe-side upper region, the titanium alloy has alpha phase crystals of a hexagonal closely packed structure whose hexagonal symmetry axis (a) is oriented in the direction of a line (k) drawn between the sweet spot (SS) and the toe end point (TP).