| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a highly repulsive cavity type iron golf club head which is thin in the central part of a face and of which the upper part has a blade part and the lower part has a thick part called as a sole part. SOLUTION: The so-called cavity type iron golf club head has the face part 2 having a hitting surface, the blade part 1 extending backward from the upper part of the face part 2 and the sole part 4 extending backward from the lower part of the face part 2. The iron golf club head has the face part 2 of <=0.25% in the face bending rigidity ratio of the face part and of >=3.0×10-3 mm/kgf in the flexibility index and the blade part 1 of >=0.93% in the blade rigidity of the blade part. Further, the entire part rigidity of the entire part of the iron golf club head is >=1.5×108 kgfmm2 and the entire part torsional rigidity thereof is >=4.0×108 kgfmm2.</p> |
