US Patent 7901297 Golf club head

This invention provides a golf club head including a plurality of score lines on the face. The golf club head includes a plurality of striations formed on the face and extending from a toe side to a heel side. A depth Dp of each striation satisfies 10 μm≦Dp≦40 μm. A cross-sectional shape of each striation is an isosceles trapezoid having an upper base at the face side and a lower base at the back side of the golf club head. The upper base and lower base satisfy the upper base>the lower base. A width Pb of the bottom portion of each protrusion formed between the striations and a width Wb of the lower base satisfy Pb<Wb.