Golf club head

Abstract

A golf club head includes a striking face having a face center and defining a face plane, a virtual vertical center plane perpendicular to the face plane and passing through the face center, a sole portion, a top portion, a heel portion, a toe portion, a hosel configured to receive a shaft, and a loft, L, no less than 39°. A center of gravity is spaced from the vertical center plane by a distance, D7. A moment of inertia, Iyy, is measured about an axis extending in a heel to toe direction, parallel with a ground plane, and passes through the center of gravity, such that Iyy/D7≥527.4 g·cm/°×L−23,580 g·cm.

We claim: 
     
         1 . A golf club head that, when oriented in a reference position relative to a virtual ground plane, comprises:
 a sole portion;   a top portion opposite the sole portion;   a heel portion;   a toe portion opposite the heel portion;   a hosel configured to receive a shaft; and   a striking face comprising a face center, defining a virtual striking face plane, and having a base surface and a plurality of scorelines recessed from the base surface, a portion of the base surface having an average surface roughness, Ra, no greater than 180 μin and a root mean square slope, Sdq, between 11° and 13°.   
     
     
         2 . The golf club head of  claim 1 , wherein the portion of the base surface further comprises an Ra of between about 120 μin and 180 μin. 
     
     
         3 . The golf club head of  claim 1 , further comprising a loft no less than 39°. 
     
     
         4 . The golf club head of  claim 1 , wherein the portion of the base surface further comprises an Rz no greater than 1000. 
     
     
         5 . The golf club head of  claim 1 , further comprising a wedge-type golf club head. 
     
     
         6 . The golf club head of  claim 1 , further comprising:
 a center of gravity;   a moment of inertia, Iyy, measured about an axis parallel with the virtual ground plane, extending in a heel to toe direction, and passing through the center of gravity, Iyy being no less than 1000 g·cm 2 .   
     
     
         7 . The golf club head of  claim 1 , further comprising:
 a virtual vertical plane perpendicular to the striking face plane and passing through the face center; and   a center of gravity spaced from the virtual vertical plane by a distance, D7, no greater than 2.5 mm.   
     
     
         8 . A golf club head that, when oriented in a reference position relative to a virtual ground plane, comprises:
 a sole portion;   a top portion opposite the sole portion;   a heel portion;   a toe portion opposite the heel portion;   a hosel configured to receive a shaft;   a striking face comprising a face center, defining a virtual striking face plane, and having a base surface and a plurality of scorelines recessed from the base surface, a portion of the base surface having an average surface roughness, Ra, no greater than 180 μin, a root mean square slope, Sdq, no less than 11° and a reduced valley depth to core ratio, Spk/Sk, of no greater than 2.   
     
     
         9 . The golf club head of  claim 8 , wherein the portion of the base surface further comprises an Ra of between about 120 μin and 180 μin. 
     
     
         10 . The golf club head of  claim 8 , further comprising a loft no less than 39°. 
     
     
         11 . The golf club head of  claim 8 , wherein the portion of the base surface further comprises an Rz no greater than 1000. 
     
     
         12 . The golf club head of  claim 8 , further comprising a wedge-type golf club head. 
     
     
         13 . The golf club head of  claim 8 , further comprising a moment of inertia, Iyy, measured about an axis parallel with the virtual ground plane, extending in a heel to toe direction, and passing through the center of gravity, Iyy being no less than 1000 g·cm 2 . 
     
     
         14 . A correlated set of club heads, comprising:
 a first and second club head, each having:
 a sole portion; 
 a top portion opposite the sole portion; 
 a heel portion; 
 a toe portion opposite the heel portion; and 
 a hosel configured to receive a shaft, 
   wherein:
 the first club head has a first loft, a first striking face having a first base surface, and a first plurality of scorelines recessed from the first base surface, a first portion of the first base surface having a first root mean square slope, Sdq, between 11° and 13° and a first average surface roughness, Ra1, no greater than 180 μin; and 
 the second club head has a second loft greater than the first loft, a second striking face having a second base surface, and a second plurality of scorelines recessed from the second base surface, a second portion of the second base surface having a second root mean square slope, Sdq, between 11° and 13° and a second average surface roughness, Ra2, greater than Ra1 and no greater than 180 μin. 
   
     
     
         15 . The golf club head of  claim 14 , wherein Ra1 and Ra2 are each between about 120 μin and 180 μin. 
     
     
         16 . The golf club head of  claim 14 , wherein the first loft is no less than 39°. 
     
     
         17 . The golf club head of  claim 14 , wherein the first portion of the first base surface further comprises an Rz no greater than 1000. 
     
     
         18 . The golf club head of  claim 14 , wherein the first and second club heads further comprise wedge-type golf club heads. 
     
     
         19 . The golf club head of  claim 14 , wherein the first club head further comprising a moment of inertia, Iyy, measured about an axis parallel with the virtual ground plane, extending in a heel to toe direction, and passing through a first center of gravity, Iyy, being no less than 1000 g·cm 2 .