Patent 7824279 was granted and assigned to Bridgestone on November, 2010 by the United States Patent and Trademark Office.
This invention provides a golf club head including a plurality of score lines on a face. In the golf club head according to this invention, the angle between each side surface of the score lines and the face is 48° or more. Edges of the score lines are formed to be positioned within a second virtual circle with a radius of 0.011 inches, the second virtual circle being concentric with a first virtual circle which internally touches the side surface of the score line and the face with a radius of 0.010 inches.