Patent ID: 7618331

Claim:
A golf club head comprising: a face portion having a front face defining the club face and a rear face facing a hollow; a crown portion; and a sole portion, wherein said face portion is provided on the rear face with: a central region defining the largest thickness of the face portion; an upper rib extending from the central region toward the crown portion; a lower rib extending from the central region toward the sole portion; a toe-side groove extending from the central region toward the toe; a heel-side groove extending from the central region toward heel; a toe-side upper region between the toe-side groove and the upper rib; a toe-side lower region between the toe-side groove and the lower rib; a heel-side upper region between the heel-side groove and the upper rib; and a heel-side lower region between the heel-side groove and the lower rib, so as to have a thickness distribution satisfying each of the following thickness magnitude relations: Central region≧Upper rib; Central region≧Lower rib; Upper rib>Toe-side upper region>Toe-side groove; Lower rib>Toe-side lower region>Toe-side groove; Upper rib>Heel-side upper region>Heel-side groove; and Lower rib>Heel-side lower region>Heel-side groove.