Patent ID: 7097572

Claim:
A hollow metal club head comprising a face portion whose front surface defines a club face for hitting a ball, and a turnback wall extending backward from a 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, a surface area of the club face is in a range of from 4000 to 6500 sq.mm, and 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 of the peripheral zone to a zone rigidity Rh of the front end zone is in a range of from 4.0 to 12.0, wherein Rh=Eh×th 3 Rf=Ef×tf 3 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.