Abstract: Disclosed herein is a driver-type golf club head that is made from at least one first material, having a density between 0.9 g/cc and 3.5 g/cc, at least one second material, having a density between 3.6 g/cc and 5.5 g/cc, and at least one third material, having a density between 5.6 g/cc and 20.0 g/cc. The first material has a first mass no more than 55% and no less than 25% of the total mass of the golf club head. The second material has a second mass no more than 65% and no less than 20% of the total mass of the golf club head. The third material has a third mass equal to the total mass of the golf club head less the first mass of the first material and the second mass of the second material.

Abstract: A method of making a golf club head includes interposing bonding tape between a first piece and a second piece of the golf club head such that the first piece is temporarily adhered to the second piece via a tackiness of the bonding tape. The method additionally includes positioning the first piece, the second piece, and the bonding tape, interposed between the first piece and the second piece, in a vacuum bag, and reducing a pressure within the vacuum bag, relative to a pressure external to the vacuum bag, such that the vacuum bag collapses onto the first piece and the second piece and compresses the bonding tape between the first piece and the second piece. The method also includes heating the bonding tape, at least to a curing temperature of the bonding tape, when the pressure within the vacuum bag is reduced.

Abstract: Disclosed herein is a driver-type golf club head that is made from at least one first material, having a density between 0.9 g/cc and 3.5 g/cc, at least one second material, having a density between 3.6 g/cc and 5.5 g/cc, and at least one third material, having a density between 5.6 g/cc and 20.0 g/cc. The first material has a first mass no more than 55% and no less than 25% of the total mass of the golf club head. The second material has a second mass no more than 65% and no less than 20% of the total mass of the golf club head. The third material has a third mass equal to the total mass of the golf club head less the first mass of the first material and the second mass of the second material.

Abstract: A golf club head that comprises a hollow interior cavity, a first piece, a second piece, adhesively bonded to the first piece along a first bonded joint, a third piece, adhesively bonded to the first piece along a second bonded joint, and a fourth piece, adhesively bonded to the first piece along a third bonded joint. A volume of the golf club head is at least 120 cubic centimeters (cc) and at most 600 cc. The first bonded joint has a first-joint bond area. The second bonded joint has a second-joint bond area. The third bonded joint has a third-joint bond area. A summation of the first-joint bond area, the second-joint bond area, and the third-joint bond area is at least 1,950 mm2 and at most 3,400 mm2.

Abstract: A golf club head has a cast cup including a forward portion of a crown and a forward portion of a sole of the golf club head. A polymeric rear ring is coupled to heel and toe portions of the cast cup to form a club head body defining a crown opening and a sole opening. A crown insert is coupled to the crown opening, and a sole insert coupled to the sole opening. The club head has an inertia generator including an outwardly extending protrusion formed in the sole and a rear weight positioned at an aft end of the protrusion, the sole insert defining at least a portion of the protrusion of the inertia generator. The sole insert includes a composite material having a thickness between 0.45 mm and 1 mm, and a plurality of ribs positioned along an internal surface, and at least one rib is inside the inertia generator.

Abstract: A golf club head that includes a plate opening, a plate-opening recessed ledge defining the plate opening, and a strike plate attached to the plate-opening recessed ledge. The golf club head also comprises a hollow interior cavity. At least a portion of a top half of the plate-opening recessed ledge is made of a first material having a first density and at least a portion of a bottom half of the plate-opening recessed ledge is made of a second material having a second density that is greater than the first density. The top half of the plate-opening recessed ledge is closer to a crown portion of the golf club head than the bottom half of the plate-opening recessed ledge and the bottom half of the plate-opening recessed ledge is closer to a sole portion of the golf club head than the top half of the plate-opening recessed ledge.

Abstract: Disclosed herein is a driver-type golf club head that has a strike face. The strike face has a central region, defined by a 40 mm by 20 mm rectangular area centered on a geometric center of the strike face and elongated in a heel-to-toe direction. The driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at any point within the central region is less than 256 microseconds and the CT at the geometric center of the strike face is no more than five microseconds different than the initial CT value.

Abstract: Disclosed herein is a driver-type golf club head that has a strike face. The strike face has a central region, defined by a 40 mm by 20 mm rectangular area centered on a geometric center of the strike face and elongated in a heel-to-toe direction. The driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at any point within the central region is less than 256 microseconds and the CT at the geometric center of the strike face is no more than five microseconds different than the initial CT value.

Abstract: Disclosed herein is a driver-type golf club head that is made from at least one first material, having a density between 0.9 g/cc and 3.5 g/cc, at least one second material, having a density between 3.6 g/cc and 5.5 g/cc, and at least one third material, having a density between 5.6 g/cc and 20.0 g/cc. The first material has a first mass no more than 55% and no less than 25% of the total mass of the golf club head. The second material has a second mass no more than 65% and no less than 20% of the total mass of the golf club head. The third material has a third mass equal to the total mass of the golf club head less the first mass of the first material and the second mass of the second material.

Abstract: Disclosed herein is a driver-type golf club head that has a strike face. The strike face has a central region, defined by a 40 mm by 20 mm rectangular area centered on a geometric center of the strike face and elongated in a heel-to-toe direction. The driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at any point within the central region is less than 256 microseconds and the CT at the geometric center of the strike face is no more than five microseconds different than the initial CT value.