| 摘要 |
<p>PROBLEM TO BE SOLVED: To sufficiently show up the cavity effect improving the face rigidity. SOLUTION: A dent 4 is formed on the back face side of a head main body 3 remaining a thick periphery part, a band shaped reinforcing bridge 5 is formed from the top side 3a of the thick periphery part to the sole side 3c to form a gap between the reinforcing bridge and the dent, and the top part of the reinforcing bridge is wider than the sole part of the reinforced bridge. A weight may be equipped on the reinforcing bridge.</p> |
