Golf club head made of metal

摘要

A golf club head which includes a ball hitting face having a central portion and a peripheral portion surrounding at least a part of the central portion. The golf club head is made of a metal, and the hardness of the peripheral portion is smaller than the hardness of the central portion. The difference in the hardness between the central portion and the peripheral portion is equal to or greater than 50 in terms of the Vickers hardness, and the width of the peripheral portion of the hitting face is in a range between about 5 and 20 mm.