Golf club head

Abstract

A golf club head includes a face portion that includes a first part and a second part. The first part includes a first material. The second part includes a second material, and one surface of the second part is bonded to one surface of the first part in a thickness direction of the first part. A density of the first material is 1.3 g/cm3 or less. A density of the second material is more than the density of the first material, and is 2.9 g/cm3 or less. Another surface of the second part is a hitting surface. The another surface of the second part, serving as the hitting surface, is opposite to the one surface of the second part. The second part includes a groove recessed from the hitting surface.

What is claimed is: 
     
         1 . A golf club head, comprising:
 a face portion that includes a first part and a second part, wherein   the first part includes a first material,   the second part includes a second material, and one surface of the second part is bonded to one surface of the first part in a thickness direction of the first part,   a density of the first material is 1.3 g/cm 3  or less,   a density of the second material is more than the density of the first material, and is 2.9 g/cm 3  or less,   another surface of the second part is a hitting surface,   the another surface of the second part, serving as the hitting surface, is opposite to the one surface of the second part, and   the second part includes a groove recessed from the hitting surface.   
     
     
         2 . The golf club head according to  claim 1 , wherein
 the density of the first material is 0.7 g/cm 3  or more, and   the density of the second material is 1.5 g/cm 3  or more.   
     
     
         3 . The golf club head according to  claim 2 , wherein
 a thickness of the second part is smaller than a thickness of the first part.   
     
     
         4 . The golf club head according to  claim 3 , wherein
 the thickness of the second part is 0.2 mm or more and 0.6 mm or less.   
     
     
         5 . The golf club head according to  claim 1 , wherein
 the groove includes
 a plurality of first grooves extending in a toe-heel direction, and 
 a plurality of second grooves located between adjacent first grooves of the first grooves, and 
   widths of the second grooves are narrower than widths of the first grooves.   
     
     
         6 . The golf club head according to  claim 1 , further comprising:
 a crown portion;   a sole portion; and   a side portion, wherein   the first portion connects the crown portion and the sole portion.   
     
     
         7 . The golf club head according to  claim 6 , wherein
 the sole portion includes
 a first sole including the first material, and 
 a second sole including a third material, and 
   a density of the third material is 4.0 g/cm 3  or more and 10 g/cm 3  or less.   
     
     
         8 . The golf club head according to  claim 7 , wherein
 the second sole includes one or more attaching portions to which a weight adjusting part is attachable and from which the weight adjusting part is detachable.   
     
     
         9 . The golf club head according to  claim 8 , wherein
 the weight adjusting part includes a fourth material, and   a density of the fourth material is 2.5 g/cm 3  or more and 14 g/cm 3  or less.   
     
     
         10 . The golf club head according to  claim 6 , further comprising:
 a hosel portion to which a sleeve to be fixed to a tip of a shaft is attachable and from which the sleeve is detachable.   
     
     
         11 . The golf club head according to  claim 1 , wherein
 a volume of the golf club head is 380 cc or more.   
     
     
         12 . The golf club head according to  claim 1 , wherein
 a weight of the golf club head is 170 g or more and 210 g or less.