Abstract: A golf club head includes a face, a sole, an attachment member, an attachment part, and a rib. The face includes a ball-striking surface. The sole defines the bottom of the golf club head. The attachment member is attachable to the attachment part. The rib is formed on the internal surface of the golf club head, and at least partially surrounds the attachment part.

Abstract: A golf club set includes a plurality of golf clubs having different loft angles. The plurality of golf clubs have the same lie angle. Each loft angle difference between two golf clubs that are adjacent in a loft angle order is the same. Each club length difference between two golf clubs that are adjacent in the loft angle order is 0.125 inches (3.175 mm) (inclusive) to 0.375 inches (9.525 mm) (inclusive). A loft angle of a golf club having a minimum frequency is smaller than a loft angle of a golf club having a maximum frequency. A difference between the minimum frequency and the maximum frequency is not less than 40 cpm.

Abstract: A golf club head according to this invention is a wood type golf club head including a face portion, a crown portion, and a sole portion. A plurality of grooves are formed in the face portion. The depth of the plurality of grooves is less than 0.025 mm. Each pitch between adjacent grooves of the plurality of grooves ranges from 0.1 mm (inclusive) to 1 mm (inclusive).

Abstract: A golf club head according to this invention is a wood type golf club head including a face portion, a crown portion, and a sole portion. A plurality of grooves are formed in the face portion. The depth of the plurality of grooves is less than 0.025 mm. A film having a thickness not more than the depth is formed on the face portion by a surface treatment.

Abstract: A golf club head according to this invention is a wood type golf club head including a face portion, a crown portion, and a sole portion. A plurality of grooves are formed in the face portion. The depth of the plurality of grooves is less than 0.025 mm. Each pitch between adjacent grooves of the plurality of grooves ranges from 0.1 mm (inclusive) to 1 mm (inclusive).

Abstract: A golf club head of this invention includes a face portion, first and second interchangeable members, a first attachment portion from which the first and second interchangeable members are detachable, and a second attachment portion from which the first and second interchangeable members are detachable. The first interchangeable member is a reinforcing member that abuts against the rear surface of the face portion and restricts deformation of an abutment portion when the member is attached to the first attachment portion. The second interchangeable member is a member that does not abut against the rear surface of the face portion when the member is attached to the first attachment portion.

Abstract: A wood type golf club head includes a face portion, a crown portion, and a sole portion. The face portion includes an impact area, a toe-side area on a toe side with respect to the impact area, and a heel-side area on the heel side with respect to the impact area. At least one groove is formed in the toe-side area and/or the heel-side area. The depth of the groove is 0.025 mm (inclusive) to 0.508 mm (inclusive). A groove area occupancy in the toe-side area is different from a groove area occupancy in the heel-side area.

Abstract: A golf club head includes a crown portion and a face portion. The crown portion includes a first protruding portion arranged on the side of the face portion, and a second protruding portion arranged on the back side to be adjacent to the first protruding portion. The width of the first protruding portion in the face-back direction on a plane passing through the face center of the face portion and extending in the vertical direction is smaller than the width of the second protruding portion in the face-back direction. The protruding height of the second protruding portion is larger than the protruding height of the first protruding portion.

Abstract: A golf club head includes: a crown portion; a sole portion; a face portion; and a hosel portion. The crown portion includes a concave portion that starts from the face portion, passes through a boundary portion of the hosel portion and the crown portion, and extends toward a back side. The concave portion includes a range from the face portion toward the back side where a width of the concave portion is larger than a depth of the concave portion. The range passes on a toe side of the hosel.

Abstract: An iron type golf club head includes a body part that is provided with a face surface and a sole surface; and a hosel part that is connected to the body part. A lower part of a back surface of the body part is an expansion part that expands rearward, a slit is disposed, which penetrates the expansion part from an upper surface to a lower surface of the expansion part, an elastic body is arranged in the vicinity of an upper part of the slit.

Abstract: A golf club includes a shaft; a head mounted to the tip end of the shaft; a grip mounted to the butt end of the shaft; a first vibration damping member arranged on the head side of the shaft; and a second vibration damping member arranged on the grip side of the shaft. The first range of the shaft in which the first vibration damping member is arranged includes a position of the shaft corresponding to the top end of the hosel of the head and has a length of 25 to 250 mm in the longitudinal direction of the shaft. The second range of the shaft in which the second vibration damping member is arranged includes a position of the shaft corresponding to the tip end of the grip and has a length of 150 to 250 mm in the longitudinal direction of the shaft.

Abstract: A golf club head of the present invention includes a hosel portion in which a shaft is inserted, the hosel portion being provided on a heel side of the golf club head, and an extended portion that extends from the hosel portion to a back side of the golf club head. The extended portion includes a distal end portion on a face portion side and a rear end portion on the back side. Out of a heel-side portion and a toe-side portion of the hosel portion, the distal end portion is connected to the heel-side portion. The rear end portion is located on the toe side with respect to the distal end portion.

Abstract: A golf club head includes a head body that has a recess part at a front portion thereof, a face plate that is in a plate shape and arranged in the recess of the head body, a front surface of the face plate being for hitting a ball, and an elastic body that is made of an elastically deformable material and intervenes between the head body and the face plate, the elastic body being fixed to the head body and the face plate so that the face plate is slidable in the recess with respect to the head body. A hardness of the material of the elastic body is ranged between Shore A Hardness 10 and Shore D Hardness 80 (inclusive), and a front side elastic body arrangement surface of the head body to which the elastic body is fixed is not parallel to the front surface of the face plate.

Abstract: A contact state observation apparatus of golf ball can observe the contact phenomenon between a golf ball and a golf club which has been conventionally hidden and unobservable. The contact state observation apparatus of golf ball includes: launching means for launching a golf ball 10; an impact plate 20 with which the launched golf ball 10 impacts; and imaging means 30, provided opposite to the launching means across the impact plate 20, for shooting an image of the contact state between the golf ball 10 and the impact plate 20 at the time of impact of the golf ball 10. The impact plate 20 has, in a part where the golf ball 10 impacts, an observation hole 21 whose area is smaller than a contact area with the golf ball, and the imaging means 30 shoots the image of the contact state through the observation hole 21.

Abstract: The present invention relates to a method of manufacturing a wood type golf club head including a face portion, a crown portion, and a sole portion. The method includes a setting step of setting a surface roughness of the face portion and a step of forming the face portion based on the surface roughness set in the setting step. In the setting step, the larger a moment of inertia of the golf club head is, the larger the surface roughness outside an impact area of the face portion is set, and the smaller the moment of inertia is, the smaller the surface roughness outside the impact area of the face portion is set.

Abstract: A golf club head of this invention is a wood type golf club head including a face portion, a crown portion, and a sole portion. A plurality of grooves arrayed in the vertical direction of the face portion are formed in the face portion. The depth of the plurality of grooves is less than 0.025 mm. When pitches between, out of the plurality of grooves, grooves adjacent in the vertical direction of the face portion are represented by P1, P2, . . . , Pn sequentially from the upper side to the lower side of the face portion, P1?P2? . . . ?Pn, and P1>Pn.

Abstract: A golf club head of the present invention includes a crown portion, a face portion, and a hosel portion. The crown portion includes a turbulence-promoting portion that extends from a heel side to a toe side and a back side.

Abstract: A golf club head of the present invention includes a hosel portion in which a shaft is inserted, the hosel portion being provided on a heel side of the golf club head, and an extended portion that extends from the hosel portion to a back side of the golf club head. The extended portion includes a distal end portion on a face portion side and a rear end portion on the back side. Out of a heel-side portion and a toe-side portion of the hosel portion, the distal end portion is connected to the heel-side portion. The rear end portion is located on the toe side with respect to the distal end portion.

Abstract: A golf club head of this invention includes a sole portion and a face portion. The golf club head includes a metal member that forms the face portion. The surface of the metal member includes a plurality of score lines, and undulations continuously formed in the up-down direction of the face portion. The pitch between adjacent apexes of the undulations exceeds 3 mm. The score lines are formed at the apexes of the undulations.

Abstract: A golf club head according to this invention is a wood type golf club head including a face portion, a crown portion, and a sole portion. A plurality of grooves are formed in the face portion. The depth of the plurality of grooves is less than 0.025 mm. Each pitch between adjacent grooves of the plurality of grooves ranges from 0.1 mm (inclusive) to 1 mm (inclusive).