| 摘要 |
A hollow metal club head comprises a face portion whose front surface defines the club face, and a turnback wall extending backward from the circumferential edge of the face portion, wherein a head volume is in a range of not less than 440 cc, a height of the club face is in a range of from 55 to 85 mm, and a surface area of the club face is in a range of from 4000 to 6500 sq.mm. In a front end zone of the turnback wall and a peripheral zone of the face portion which are adjacent to each other through a junction between the turnback wall and the face portion, the ratio Rf/Rh of a zone rigidity Rf (=Efxtf<3>) of the peripheral zone to a zone rigidity Rh (=Ehxth<3>) of the front end zone is in a range of from 4.0 to 12.0, wherein "Eh" is Young's modulus in GPa of the turnback wall in the front end zone, "th" is average thickness in mm of the turnback wall in the front end zone, "Ef" is Young's modulus in GPa of the face portion in the peripheral zone, and "tf" is average thickness in mm of the face portion in the peripheral zone.
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