Abstract: A golf club head 1 having a hollow (i) therein comprises a face portion 2 having a face 2a for striking a ball, a crown portion 3 forming the head top surface, and a sole portion 4 forming a bottom of the head. One of or each of the crown portion 3 and the sole portion 4 is provided with a plurality of grooves bent in the same direction.

Abstract: Provided is a golf club head that is able to suppress lowering of the pitch of a ball hitting sound. The golf club head according to the present invention includes a crown portion, a face portion, and a sole portion having at least one recessed portion. The recessed portion is configured to house a weight member such that the weight member does not protrude externally. The sole portion is provided with a placement region connected to the face portion and to be at least partially placed on a placement surface in a reference state, and a rear region arranged further to a back side in a face-back direction than the placement region and in which the recessed portion is arranged. The rear region inclines upward relative to the placement region toward the back side.

Abstract: A golf club 100 includes a head 200 having a hosel part 202, a shaft 300, and a reverse-tapered engagement part RT. The reverse-tapered engagement part RT includes a sleeve 400 having a reverse-tapered shape and being fixed to a tip portion of the shaft 300, and a spacer fitted outside of the sleeve 400. The hosel part 202 includes a hosel hole 204 and a hosel slit 206 which is provided on a side of the hosel hole 204 and enables the shaft 300 to pass through the hosel slit. The hosel hole 204 has a reverse-tapered hole 205 having a shape corresponding to a shape of an outer surface of the reverse-tapered engagement part RT. The reverse-tapered engagement part RT is fitted to the reverse-tapered hole 205. A club length is changed by changing a wall thickness of the spacer.

Abstract: A golf club according to one aspect of the present invention includes a shaft, a golf club head including a hosel containing a hole to attach the shaft, and a sleeve system including a body attached to a tip of the shaft and inserted together with the shaft into the hole of the hosel and an adaptor attached to the body so as to enable an adjustment of an axis-directional position with respect to the body and engaging with an upper end of the hosel.

Abstract: Provided is a golf club head having a hollow structure and including a face portion, a crown portion, and a sole portion. In the sole portion, a first groove and a second groove are formed extending in a toe-heel direction and recessed toward the inside of the sole portion. The first groove is disposed on a face side relative to the second groove. The second groove is deeper than the first groove.

Abstract: A golf club 2 includes a head 4, a shaft 6, and a grip 8. The club 2 has a forward club flex of greater than or equal to 170 mm. The forward club flex is measured for a golf club in the completed state. The weight of the head is denoted by Wh, and the weight of the club is denoted by Wc. Wh/Wc is greater than or equal to 0.72. With the golf club 2, a force acting on the player's body during a swing can be reduced. The golf club 2 can stabilize swing.

Abstract: A head 2 includes a face part 4. The face part 4 includes a plurality of constant thickness regions S1 and S2, and a plurality of thickness transition regions R1, R2 and R3. The constant thickness regions include a first constant region S1 and a second constant region S2 which is thinner than the first thickness region S1. The thickness transition regions R1, R2 and R3 which are adjacent to each other is disposed between the first constant region S1 and the second constant region S2. The thickness transition regions adjacent to each other have different thickness change rates from each other.

Abstract: A shaft of a golf club includes a reverse-tapered engagement part. The reverse-tapered engagement part includes a sleeve having a reverse-tapered shape, and a reverse-tapered outer surface. A hosel part of a head includes a reverse-tapered inner surface and a hosel slit. A hosel hole includes the reverse-tapered inner surface having a shape corresponding to that of the reverse-tapered outer surface. Either one of the reverse-tapered outer surface and the reverse-tapered inner surface includes an abutting engagement surface and a non-abutting engagement surface. The other of the reverse-tapered outer surface and the reverse-tapered inner surface includes a first abutting surface and the second abutting surface. In the golf club, a first state and a second state in which club lengths are different from each other can be achieved.

Abstract: A golf club includes a head, a shaft, and a grip. The golf club has a club vibration frequency of less than or equal to 210 cpm. The golf club has a club length of greater than or equal to 45.7 inches and less than or equal to 46.5 inches. With the golf club, a force acting on the player's body during a swing can be reduced. The golf club can stabilize swing.

Abstract: A golf club includes a head, a shaft, and a grip. The golf club has a club vibration frequency of less than or equal to 210 cpm. The golf club has a swing weight of greater than or equal to D5. With the golf club, a force acting on the player's body during a swing can be reduced. The golf club can stabilize swing.

Abstract: A golf club 2 includes a head 4, a shaft 6, and a grip 8. The club 2 has a forward club flex of greater than or equal to 140 mm. The forward club flex is measured for a golf club in the completed state. The grip 8 has a weight Wg of less than or equal to 30 g. With the golf club 2, a force acting on the player's body during a swing can be reduced. The golf club 2 can stabilize swing.

Abstract: A golf club 2 includes a head 4, a shaft 6, and a grip 8. The club 2 has a forward club flex of greater than or equal to 170 mm. The forward club flex is measured for a golf club in the completed state. The weight of the head is denoted by Wh, and the weight of the club is denoted by Wc. Wh/Wc is greater than or equal to 0.72. With the golf club 2, a force acting on the player's body during a swing can be reduced. The golf club 2 can stabilize swing.

Abstract: A golf club head according to the present invention includes: a head main body including a crown part and a sole part, and having an opening surrounded by the crown part and the sole part; and a face member covering the opening in the head main body. The face member is formed in a cup-like shape, including a face part formed in a planar shape and a peripheral edge part extending from a peripheral edge of the face part. An end surface forming the opening in the head main body is formed extending parallel to the face part. The crown part of the head main body includes: a front-side region extending in a toe-heel direction along an edge part on the side where the opening is located; and a rear-side region located further on a back side than the front-side region and being thinner than the front-side region.

Abstract: The golf club head includes a crown portion, a face portion and a sole portion. The crown portion is formed to have an average thickness, in a range of a predetermined length toward a back side from a boundary between the crown portion and the face portion, that is larger in a vicinity of a center in a toe-heel direction than at a toe side and a heel side.

Abstract: A golf club 100 includes a tip engagement part RT having a reverse-tapered shape and being disposed at a tip end portion of a shaft 300, and a screw member 600. The tip engagement part RT includes a sleeve 400 fixed to the tip end portion of the shaft 300. The sleeve 400 has a sleeve-side connection part 410. The screw member 600 has a screw-side connection part 602 that can be detachably connected to the sleeve-side connection part 410, and a male screw part 604. The head 200 has a female screw part 220. When the screw member 600 is rotated in a first direction, the screw member 600 presses the tip engagement part RT in an engaging direction. When the screw member 600 is rotated in a second direction, the screw member 600 pulls the tip engagement part RT in an engagement releasing direction.

Abstract: Provided is a golf club head having a sole portion. In the sole portion, first and second grooves are formed extending in a toe-heel direction and recessed toward the inside of the sole portion. The first groove is disposed on a face side relative to the second groove. The first groove includes a first main inner wall and a first sub inner wall shorter than the first main inner wall. The second groove includes a second main inner wall and a second sub inner wall shorter than the second main inner wall. The first and second main inner walls are inclined so as to point upward toward the face side. The second main inner wall, when the sole portion has been placed on a ground plane, is inclined more steeply than the first main inner wall relative to the ground plane in a side cross-sectional view.

Abstract: A golf club head having a striking face configured to impact a golf ball comprises the striking face comprising an effective striking area, the effective striking area having an expected COR value, defined by the following expression, not less than 0.810, Expected ? ? COR = ? i = 1 n ? ? j = 1 m ? p ij * c ij wherein pij is an impact probability at location or region (i, j) within the effective striking area, and cij is a COR value of the location or region (i, j).

Abstract: A head 2 includes a face 10 and a sole 6. The face 10 has a face center Fc. The sole 6 includes a groove 20 extending from a toe side to a heel side. The whole groove 20 is located below the face center Fc. A bottom part of the groove 20 is curved so that it projects to a lower side along a shape of the sole 6. A maximum value of a groove depth D of the groove 20 is 5% or greater but 15% or less of a height of a center of gravity of the head. The head 2 is a hollow golf club head.

Abstract: A sole 6 of a head 2 includes a groove 20 extending from a toe side to a heel side. The groove 20 includes a center groove part 20c, a toe groove part 20t, and a heel groove part 20h. A toe boundary line kt is formed on a boundary between the center groove part 20c and the toe groove part 20t due to the change of a groove depth D. A heel boundary line kh is formed on a boundary between the center groove part 20c and the heel groove part 20h due to the change of the groove depth D. The toe groove part 20t and the heel groove part 20h extend so as to be inclined with respect to a face-back direction. The head 2 is a hollow golf club head.

Abstract: A golf club head 1 having a hollow (i) therein comprises a face portion 2 having a face 2a for striking a ball, a crown portion 3 forming the head top surface, and a sole portion 4 forming a bottom of the head. One of or each of the crown portion 3 and the sole portion 4 is provided with a plurality of grooves bent in the same direction.