Golf club head

Abstract

A golf club head has a face portion with a thick-walled portion located in the center of the face portion and an outer peripheral portion located on an outer periphery of the thick-walled portion. The thick-walled portion has a central portion of the face portion having a largest thickness, a first ridge which surrounds the central portion and has a smaller thickness than the central portion, and a first valley which is located between the central portion and the first ridge and has a smaller thickness than the first ridge. The golf club head maintains a low weight of a face portion and suppresses dispersion of CT values at each hitting point so that the CT values at hitting points other than a sweet spot are substantially equal to the CT value at the sweet spot.

1 . A golf club head comprising a face portion formed of metallic material, the face portion comprising a thick-walled portion located in the center of the face portion and an outer peripheral portion located on an outer periphery of the thick-walled portion, and the thick-walled portion comprising a central portion of the face portion having a largest thickness, a first ridge which surrounds the central portion and has a smaller thickness than the central portion, and a first valley which is located between the central portion and the first ridge and has a smaller thickness than the first ridge. 
     
     
         2 . A golf club head according to  claim 1 , wherein the thick-walled portion has a shape depressed substantially circularly toward the center of the face portion on two sides opposing each other of a substantially circular shape or a substantially elliptical shape. 
     
     
         3 . A golf club head according to  claim 2 , wherein the substantially circular depressions are so configured that the depression on the toe side is directed obliquely with respect to the sole direction and the depression on the heel side is directed obliquely with respect to the crown direction. 
     
     
         4 . A golf club head according to  claim 1 , wherein the length from the upper side to the lower side of the first valley is 30 to 50% the height of the face portion passing through the center of the face portion. 
     
     
         5 . A golf club head according to  claim 1 , wherein the length from the upper side to the lower side of the first ridge is 40 to 60% the height of the face portion passing through the center of the face portion. 
     
     
         6 . A golf club head according to  claim 1 , wherein a difference between the thickness of the central portion and the thickness of the first ridge is 0.05 to 0.5 mm, and a difference between the thickness of the first ridge and the thickness of the first valley is 0.05 to 0.3 mm. 
     
     
         7 . A golf club head according to  claim 1 , wherein the thick-walled portion further comprises a second ridge which surrounds the first ridge and has a smaller thickness than the first ridge, and a second valley which is located between the first ridge and the second ridge and has a smaller thickness than the second ridge.