| 摘要 |
A face backside of a golf club head is provided with six or more ribs extended from a face center toward face circumferences. Angles theta1 to theta6 between respective pairs of adjoining ones of the ribs are less than 90°. One of the ribs that form the smallest angle between its extension direction and a head vertical direction d1 and that extends from the face center toward a crown-side face circumference constitutes an upward rib, which has a smaller cross-sectional area than any of those of the other ribs.
|
