Patent ID: 8540590

Claim:
A hollow golf club head comprising a club head plate including thinned parts and ribs protruded therefrom, said thinned parts and ribs being formed by chemically polishing a certain area on a surface of a material of said club head plate to adjust weight and thickness of said club head plate; wherein the chemically-polished area on the surface of the material of said club head plate comprises: a first area on which a plurality of said ribs are formed, and a second area surrounded with the plurality of said ribs to define said thinned parts, wherein the thickness of the material of said club head plate is greater than that of said first area, and that of said first area is greater than that of said second area; and wherein the surface of the material of said club head plate is located on an inside of a crown plate, and said ribs are formed to have a thickness not less than 0.4 mm but less than the thickness of the material for the club head plate as well as a width in a range of from 0.4 to 4 mm, while said thinned parts are formed to have a thickness in a range of from 0.2 to 0.5 mm.