Golf club head

Abstract

This invention provides a golf club head including a plurality of score lines on a face. In the golf club head according to this invention, the angle between each side surface of the score lines and the face is 48° or more. Edges of the score lines are formed to be positioned within a second virtual circle with a radius of 0.011 inches, the second virtual circle being concentric with a first virtual circle which internally touches the side surface of the score line and the face with a radius of 0.010 inches.

1 . A golf club head including a plurality of score lines on a face, wherein an angle between each side surface of said score lines and said face is not less than 48 degrees, and,
 edges of said score lines are formed to be positioned within a second virtual circle with a radius of 0.011 inches, the second virtual circle being concentric with a first virtual circle which internally touches said side surface and said face with a radius of 0.010 inches.   
     
     
         2 . The golf club head according to  claim 1 , wherein a cross sectional shape of each edge of said score lines is a circular arced shape with a radius not more than 0.1 mm. 
     
     
         3 . The golf club head according to  claim 1 , wherein each edge of said score lines comprises a flat surface inclined against both of said face and said side surface. 
     
     
         4 . The golf club head according to  claim 3 , wherein an angle θ 1  (°) between each side surface of said score lines and said face and an angle θ 2  (°) between said flat surface and said face satisfy the following expression:
   θ1−49.24<θ2<49.24.   
     
     
         5 . The golf club head according to  claim 1 , wherein each edge of said score lines comprises a notch. 
     
     
         6 . The golf club head according to  claim 5 , wherein a cross sectional shape of said notch is arced. 
     
     
         7 . The golf club head according to  claim 6 , wherein the cross sectional shape of said notch is a circular arc with a radius not more than 0.4 mm. 
     
     
         8 . The golf club head according to  claim 5 , wherein said notch comprises a first side surface leading to said face and a second side surface leading to said first surface and said side surface of said score line. 
     
     
         9 . The golf club head according to  claim 1 , wherein a cross section area A (inch 2 ) of said score line, a width W (inch) of said score line measured based on the 30 degrees measurement rule and a distance S (inch) between said score lines adjacent one another satisfy the following expression:
     A /( W+S )≦0.0025.