Abstract: A hollow golf club head includes a face portion, a sole portion, a side portion, a crown portion and a hosel portion. A main portion of the crown portion is made of a fiber plastic resin. At least the face portion, a front edge portion of the crown portion continuous with the face portion, and a central portion of the sole portion in a toe-heel direction are made of a metal. A loft angle is in a range of 14° to 25°. A head volume is in a range of 100 cc to 230 cc. A weight of a fiber plastic resin portion of the golf club head is in a range of 6% to 30% of a weight of the golf club head.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 1.0 to 3.0 mm. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. Dimples of the number of 300 to 550 pieces are formed in the surface of the golf ball in such a manner that a dimple total volume ratio VR is in a range of 0.85% or less. The multi-piece golf ball is excellent in resilience, flight distance characteristic, and feel of hitting.

Abstract: A hollow golf club head includes a fiber-reinforced-plastic body and a metal body. The fiber-reinforced-plastic body includes a main portion of a crown portion. The metal body includes a face portion, a front edge portion of the crown portion continuous with the face portion, and a central portion of a sole portion in a toe-heel direction. The front edge portion of the crown portion made of a metal defines a recess portion in an upper surface thereof. A front edge portion of the fiber-reinforce-resin body overlaps and is joined to the front edge portion of the crown portion made of the metal.

Abstract: A hollow golf club head includes a face portion made of metal, a sole portion, a side portion, a crown portion, and a hosel portion. The crown portion includes a main portion made of a fiber reinforced resin, and a front edge portion made of the metal. The front edge portion of the crown portion is continuous with the face portion. The sole portion comprises a center portion made of the metal in a toe-heel direction. A weight of a portion made of the fiber reinforced resin including the main portion of the crown portion is in a range of 5% to 30% of a total weight of the golf club head.

Abstract: An iron-type golf club head has a face which has a face surface of a flat shape, and a hosel which is continuous with the face on its heel side. A shaft insertion hole is disposed in the hosel. A protrusion protruding rearward is disposed in the vicinity of the center in a toe-heel direction. A material of the golf club head is pure iron having a high purity of at least 99.8%, for instance, pure iron having a purity within a range of 99.995 to 99.9999%. The golf club head is subjected to carburizing so that carbon diffuses up to about 0.2 to 0.5 mm from the surface. A region within 0.2 mm from the face surface has a hardness of HV 300 to 600, and a region where a distance from the face surface is 0.7 mm or more has a hardness of HV 100 or lower.

Abstract: An iron-type golf club head has a face having a face surface of a flat surface, and a hosel which is continuous with the face on its heel side. A shaft insertion hole is disposed in the hosel. A protrusion protruding rearward in the vicinity of the center in a toe-heel direction is disposed. A material of the golf club head is pure iron having a high purity of at least 99.995%, for instance, a purity within a range of 99.995 to 99.9999%. The golf club head is subjected to carburizing so that carbon diffuses to a range of about 0.2 to 0.5 mm from the surface.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 1.0 to 3.0 mm. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. Dimples of the number of 300 to 550 pieces are formed in the surface of the golf ball in such a manner that a dimple total volume ratio VR is in a range of 0.85% or less. The multi-piece golf ball is excellent in resilience, flight distance characteristic, and feel of hitting.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 1.0 to 3.0 mm. The core is made from a rubber composition mainly containing polybutadiene. The outermost layer is made from a non-ionomer based thermoplastic resin. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. The core has a hardness corresponding to a deflection in a range of 3.5 to 6.5 mm under an applied load of 100 kg.

Abstract: A multi-piece solid golf ball comprising a solid core and a cover of two inner and outer layers surrounding the core. The outer cover layer has a surface formed with a plurality of three types of dimples such that a product of the Shore D hardness of the inner cover layer multiplied by the Shore D hardness of the outer cover layer and a proportion VR (%) of the total of the volumes of dimple spaces satisfy one of: (1) 1,500 to less than 2,000 VR: 0.8 to 1.1% (2) 2,000 to less than 2,500 VR: 0.75 to 1.05% (3) 2,500 to less than 3,000 VR: 0.7 to 1% (4) 3,000 to less than 3,500 VR: 0.65 to 0.95% (5) 3,500 to 4,000 VR: 0.6 to 0.9%.

Abstract: A golf club head includes a front body formed of a titanium-based metal material, an FRP body, a metallic sole plate, and a weight member. The front body has a face portion, a metal sole portion, a metal side portion (toe), a metal crown portion, a metal side portion (heel), and a hosel portion. A slight gap is formed between a front side of the sole plate and the metal sole portion. Preferably, the front body is made of a titanium alloy, while the sole plate is made of stainless steel.

Abstract: A golf club head includes a front body formed of a metal material, an FRP body, a metallic sole plate, and a weight member. The front body has a face portion, a metal sole portion, a metal side portion (toe), a metal crown portion, a metal side portion (heel), and a hosel portion. A slight gap in a range of 4 mm to 12 mm is formed between a front side of the sole plate and the metal sole portion. This part is formed of the FRP body. Preferably, the metal material of the front body includes a titanium-based alloy or a zirconium-based amorphous alloy. The sole plate is made of stainless steel.

Abstract: A golf club head includes a front body formed of a titanium-based metal material, an FRP body, a metallic sole plate, and a weight member. The front body has a face portion, a metal sole portion, a metal side portion (toe), a metal crown portion, a metal side portion (heel), and a hosel portion. A slight gap is formed between a front side of the sole plate and the metal sole portion. Preferably, the front body is made of a titanium alloy, while the sole plate is made of stainless steel. The height of center of gravity (mm) and the head volume V have a relationship of H?0.05V+7.5.

Abstract: An iron golf club head includes a head main body and an FRP body. The head main body includes a face portion, a first face along the face portion, second faces, and a recess behind the head portion. The second faces continue from a rear face of the face portion to the first face. The recess is defined by the first face and the second faces. The hollow FRP body is disposed in the recess, overlaps the first face and the second faces, and closes an opening portion of the recess. At least a part of crossing corner portions between the first face and the second faces has a curved face.

Abstract: A multi-piece solid golf ball comprises a solid core and a cover of two inner and outer layers surrounding the core. The outer cover layer has a surface formed with a plurality of dimples is characterized in that a product of the Shore D hardnesses of the inner cover layer multiplied by the Shore D hardnesses of the outer cover layer and a proportion VR (%) of the total of the volumes of dimple spaces each defined below a plane circumscribed by the dimple edge to the overall volume of a phantom sphere given on the assumption that the golf ball surface is free of dimples satisfy any one of the following combinations (1) to (5): (1) 1,500 to less than 2,000 VR: 0.8 .to 1.1% (2) 2,000 to less than 2,500 VR: 0.75 to 1.05% (3) 2,500 to less than 3,000 VR: 0.7 to 1% (4) 3,000 to less than 3,500 VR: 0.65 to 0.95% (5) 3,500 to 4,000 VR: 0.6 to 0.9%.

Abstract: In a multi-piece solid golf ball comprising a solid core, a cover inner layer and a cover outer layer, the solid core undergoes a deflection of 3-7 mm under a load of 100 kg, the cover inner layer has a Shore D hardness of 25-58 and a thickness of 0.5-1.4 mm, the cover outer layer has a Shore D hardness of 30-62 and a thickness of 1.2-2.3 mm, and the ratio of the thickness of the cover outer layer to the thickness of the cover inner layer is from 1.1 to 4.6. The ball is improved in playability, feel and durability.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 0.5 to 2.0 mm. The core is made from a rubber composition mainly containing polybutadiene. The outermost layer is made from a resin material containing an ionomer resin in an amount of 30% by weight or more. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. The hardness of said cover is smaller than the hardness of said outermost layer of said at least one intermediate layer and is larger than the hardness of a center portion of said core. The multi-piece golf ball is excellent in resilience, durability, feel of hitting, and controllability.

Abstract: In a multi-piece solid golf ball comprising a solid core, an enclosure layer, an intermediate layer, and a cover, the enclosure layer and the intermediate layer each have a Shore D hardness of 10-50, the enclosure layer's Shore D hardness≦the intermediate layer's Shore D hardness≦the cover's Shore D hardness, and the deflections under a load of 100 kg of the solid core, a first spherical body consisting of the solid core and the enclosure layer, a second spherical body consisting of the solid core, the enclosure layer and the intermediate layer, and the ball are controlled to fall in specific ranges. The cover is formed of a cover stock comprising an ionomer resin and an inorganic filler.

Abstract: The present invention is a two-piece golf ball which includes a core and a cover having a thickness of 1.0 to 3.0 mm. The core is made from a rubber composition containing a main rubber component which mainly contains polybutadiene. The cover is made from a material mainly containing an ionomer resin in which at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof is dispersedly blended. The core has a hardness corresponding to a deflection in a range of 3.3 to 6.0 mm under an applied load of 100 kg. The cover has a Durometer D hardness in a range of 55 to 70.

Abstract: A two-piece golf ball includes a core and a cover having a thickness of 0.5 to 2.5 mm. The core has a hardness corresponding to a deflection in a range of 3.0 to 5.5 mm under a load of 100 kg. The cover has a Durometer D hardness 45 to 55. Dimples numbering 300 to 550 pieces are formed in the surface of the golf ball so that a dimple total volume ratio VR, which is a ratio of the total of volumes of dimple spaces under the planes surrounded by edges of the dimples in the surface of the golf ball to the total volume of a virtual ball as a result of assumption that no dimple is formed in the surface of the golf ball, is 0.85% or less. The two-piece golf ball is excellent in resilience, flight distance characteristic, controllability, and feel of hitting.

Abstract: In a solid golf ball comprising a solid core and a cover, provided that a coefficient of restitution at a firing velocity of v m/s is designated by CORv, a ball structure prior to formation of the cover satisfies COR25-COR50≧0.100, and the ball satisfies COR50≧0.740 and COR25-COR50≧0.09. The golf ball's performance depends little on the head speed so that the flight performance of the ball when hit at a low head speed is improved while the flight performance when hit at a high head speed is little deteriorated.