Golf club head

Abstract

An iron-type golf club head includes a heel, a toe, a top portion, a sole portion, a top portion, a rear portion, and a striking wall. The striking wall includes a striking face having a plurality of scorelines and a face center and a rear surface. A minimum striking wall thickness Tmin is no greater than 2.5 min. A thickened central region of the striking wall has a maximum thickness, Tmax, greater than Tmin but no greater than 2.75. A first thickness T1 of the striking wall corresponds with a first location spaced toe-ward from the face center by a first distance D1 of between 20 mm and 30 mm. A second thickness T2 of the striking wall corresponds with a second location spaced heel-ward from the face center by the first distance D1 such that T1 is greater than T2 by no less than 0.05 mm.

What is claimed is: 
     
         1 . A set of golf club heads comprising:
 a first golf club head that, when oriented in a reference position, comprises a hollow-type golf club head and has a first loft, L1, between 18° and 28°; and   a second golf club head that, when oriented in a reference position, comprises a cavity-back golf club head and has a second loft, L2, between 34° and 50°;   wherein each golf club head of the set of golf club heads comprises a center of gravity and a moment of inertia, Izz, about a virtual vertical axis passing through the center of gravity, and   wherein the standard deviation of all the moments of inertia of the golf club heads of the set is no greater than 100 g·cm 2 .   
     
     
         2 . The set of golf club heads of  claim 1 , wherein the standard deviation is no greater than 80 g·cm 2 . 
     
     
         3 . The set of golf club heads of  claim 1 , wherein the standard deviation is no greater than 75 g·cm 2 . 
     
     
         4 . The set of golf club heads of  claim 1 , wherein:
 the moment of inertia of the first golf club head, Izz(1), is no less than 2500 g*cm 2 ; and   the moment of inertia of the second golf club head, Izz(2), is no less than 2500 g*cm 2 .   
     
     
         5 . The set of golf club heads of  claim 4 , wherein:
 the moment of inertia of the first golf club head, Izz(1), is between 2525 g·cm 2  and 2800 g·cm 2 ; and   the moment of inertia of the second golf club head, Izz(2), is between 2525 g·cm 2  and 2800 g·cm 2 .   
     
     
         6 . The set of golf club heads of  claim 1 , wherein the first golf club head and the second golf club head each comprise a head mass no greater than about 300 g. 
     
     
         7 . The set of golf club heads of  claim 1 , wherein the first golf club head further comprises a top portion, a sole portion, a striking wall, and a rear portion that form a substantially enclosed interior cavity, the interior cavity including at least one stiffening element secured to at least one of the sole portion and the top portion. 
     
     
         8 . The set of golf club heads of  claim 1 , wherein:
 the first club head further comprises a first striking face and a first center of gravity spaced rearwardly from the first striking face by a distance Dcg1 that satisfies the following: Dcg1≥−0.0648 mm/°*L1+7.6 mm; and   the second club head further comprises a second striking face and a second center of gravity spaced rearwardly from the second striking face by a distance Dcg2 that satisfies the following: Dcg2≥−0.0648 mm/°*L2+7.6 mm.   
     
     
         9 . The set of golf club heads of  claim 1 , wherein:
 the first club head further comprises a mass m1 no greater than about 300 g; and   the second club head further comprises a mass m2 no greater than about 300 g.   
     
     
         10 . A set of golf club heads comprising:
 a first golf club head that, when oriented in a reference position, comprises a hollow-type golf club head and has a first loft, L1, no greater than 28°; and   a second golf club head that, when oriented in a reference position, comprises a cavity-back golf club head and has a second loft, L2, no less than 34°;   wherein each golf club head of the set of golf club heads comprises a center of gravity and a moment of inertia, Izz, about a virtual vertical axis passing through the center of gravity, and   wherein the standard deviation of all the moments of inertia of the golf club heads of the set is no greater than 100 g·cm 2 .   
     
     
         11 . The set of golf club heads of  claim 1 , wherein the standard deviation is no greater than 80 g·cm 2 . 
     
     
         12 . The set of golf club heads of  claim 1 , wherein the standard deviation is no greater than 75 g·cm 2 . 
     
     
         13 . The set of golf club heads of  claim 1 , wherein:
 the moment of inertia of the first golf club head, Izz(1), is no less than 2500 g*cm 2 ; and   the moment of inertia of the second golf club head, Izz(2), is no less than 2500 g*cm 2 .   
     
     
         14 . The set of golf club heads of  claim 13 , wherein:
 the moment of inertia of the first golf club head, Izz(1), is between 2525 g·cm 2  and 2800 g·cm 2 ; and   the moment of inertia of the second golf club head, Izz(2), is between 2525 g·cm 2  and 2800 g·cm 2 .   
     
     
         15 . The set of golf club heads of  claim 1 , wherein the first golf club head and the second golf club head each comprise a head mass no greater than about 300 g. 
     
     
         16 . The set of golf club heads of  claim 1 , wherein the first golf club head further comprises a top portion, a sole portion, a striking wall, and a rear portion that form a substantially enclosed interior cavity, the interior cavity including at least one stiffening element secured to at least one of the sole portion and the top portion. 
     
     
         17 . The set of golf club heads of  claim 1 , wherein:
 the first club head further comprises a first striking face and a first center of gravity spaced rearwardly from the first striking face by a distance Dcg1 that satisfies the following: Dcg1≥−0.0648 mm/°*L1+7.6 mm; and   the second club head further comprises a second striking face and a second center of gravity spaced rearwardly from the second striking face by a distance Dcg2 that satisfies the following: Dcg2≥−0.0648 mm/**L2+7.6 mm.   
     
     
         18 . The set of golf club heads of  claim 1 , wherein:
 the first club head further comprises a mass m1 no greater than about 300 g; and   the second club head further comprises a mass m2 no greater than about 300 g.