A method of manufacturing a wood-type golf club head, the golf club head including a face member that forms a face portion and a main body member to which the face member is to be joined, the method including a step of forming, in the face portion of the face member, a plurality of grooves and a concave portion extending so as to surround the plurality of grooves, a step of joining by welding the main body member and the face member in which the plurality of grooves and the concave portion are formed, and a step of grinding a region from the concave portion to an end portion of the main body member, the region including a welded portion between the face member and the main body member.

A method of manufacturing a wood-type golf club head, the golf club head including a face member that forms a face portion and a main body member to which the face member is to be joined, the method including a step of forming, in the face portion of the face member, a plurality of grooves and a concave portion extending so as to surround the plurality of grooves, a step of joining by welding the main body member and the face member in which the plurality of grooves and the concave portion are formed, and a step of grinding a region from the concave portion to an end portion of the main body member, the region including a welded portion between the face member and the main body member.

A method for manufacturing a bicycle crank is revealed. After being extended, bent and forged, an aluminum alloy pipe becomes an L-shaped part formed by a cylindrical crankshaft portion and an oval crank portion integrally connected to each other. A plug is inserted into an outer end of the crank portion while a periphery of an outer end of the crankshaft portion is punched to form a shaft-connecting portion. An assembling hole is arranged at the outer end of the crank portion, corresponding to the plug. Thus a bicycle crank is produced. Thereby not only the assembly of the bicycle crank is easier and more convenient, the structural strength of the bicycle crank is increased effectively to against vibrations and impacts. The bicycle is lightweight and the bicycle crank is more streamlined so that consumers are attracted. Thereby the market competitiveness is increased.

A method for manufacturing a bicycle crank is revealed. After being extended, bent and forged, an aluminum alloy pipe becomes an L-shaped part formed by a cylindrical crankshaft portion and an oval crank portion integrally connected to each other. A plug is inserted into an outer end of the crank portion while a periphery of an outer end of the crankshaft portion is punched to form a shaft-connecting portion. An assembling hole is arranged at the outer end of the crank portion, corresponding to the plug. Thus a bicycle crank is produced. Thereby not only the assembly of the bicycle crank is easier and more convenient, the structural strength of the bicycle crank is increased effectively to against vibrations and impacts. The bicycle is lightweight and the bicycle crank is more streamlined so that consumers are attracted. Thereby the market competitiveness is increased.

A co-forged iron type golf club is disclosed. More specifically, the present invention discloses a co-forged iron type golf club with the body portion made out of a first material and at least one weight adjustment portion monolithically encased within the body portion of the co-forged iron type golf club head without the need for secondary attachment or machining operations. The present invention creates of an iron type golf club head from a pre-form billet that already contains two or more materials before the actual forging process resulting in a multi-material golf club head that doesn't require any post manufacturing operations such as machining, welding, swaging, gluing, and the like.

A co-forged iron type golf club is disclosed. More specifically, the present invention discloses a co-forged iron type golf club with the body portion made out of a first material and at least one weight adjustment portion monolithically encased within the body portion of the co-forged iron type golf club head without the need for secondary attachment or machining operations. The present invention creates of an iron type golf club head from a pre-form billet that already contains two or more materials before the actual forging process resulting in a multi-material golf club head that doesn't require any post manufacturing operations such as machining, welding, swaging, gluing, and the like.

A golf club head according to the present invention is provided with a face portion, a crown portion and a sole portion, the crown portion including a first area extending in a toe-heel direction along at least part of the face portion and a second area arranged further to a back side than the first area, a sloped surface that extends in the toe-heel direction and slopes downward approaching the back side being formed between the first area and the second area, and a transfer sheet that is formed in a shape corresponding to the sloped surface and is a different color from the first area and the second area being stuck to the sloped surface.

A golf club head includes a metallic section, a polymeric section, and an adhesive material. The metallic section defines an opening and the polymeric section extends over the opening. The adhesive material is disposed between the metallic section and the polymeric section to form an adhesive joint therebetween. The adhesive joint has an adhesive retaining strength configured to inhibit the polymeric section from being detached from the metallic section when the adhesive material is at least partially cured. The metallic section and the polymeric section are also mechanically engaged with one another to form a mechanical joint therebetween having a mechanical retaining strength configured to inhibit the polymeric section from being detached from the metallic section. The adhesive retaining strength of the adhesive joint, alone, is greater than the mechanical retaining strength of the mechanical joint, alone, only when the adhesive material is at least partially cured.

A co-forged iron type golf club is disclosed. More specifically, the present invention discloses a co-forged iron type golf club with the body portion made out of a first material and at least one weight adjustment portion monolithically encased within the body portion of the co-forged iron type golf club head without the need for secondary attachment or machining operations. The present invention creates of an iron type golf club head from a pre-form billet that already contains two or more materials before the actual final forging process resulting in a multi-material golf club head that doesn't require any post manufacturing operations such as machining, welding, swaging, gluing, and the like.

A co-forged iron type golf club is disclosed. More specifically, the present invention discloses a co-forged iron type golf club with the body portion made out of a first material and at least one weight adjustment portion monolithically encased within the body portion of the co-forged iron type golf club head without the need for secondary attachment or machining operations. The present invention creates of an iron type golf club head from a pre-form billet that already contains two or more materials before the actual final forging process resulting in a multi-material golf club head that doesn't require any post manufacturing operations such as machining, welding, swaging, gluing, and the like.