Patent ID: 8678949

Claim:
A golf club head having a hollow structure, which is made of a metal, comprising: a lower part comprising a sole part and a side part which are integrally formed, the lower part further comprising a first reinforcing piece having a first thickness and a second reinforcing piece having a second thickness greater than the first thickness, wherein the first reinforcing piece is welded on an inner surface of the sole part in a substantially halfway portion between a heel side and a toe side of the sole part and is aligned with a face side edge of the sole part, and wherein the second reinforcing piece is welded on an inner surface of the first reinforcing piece in a substantially halfway portion between a heel side and a toe side of the first reinforcing piece and is aligned with a face side edge of the first reinforcing piece; and a face part welded to the sole part and the first and second reinforcing pieces of the lower part.