Abstract: A hollow golf club head made of a metallic material. The golf club head has a three piece structure, a main head body, face, and crown. The main head body and the crown are formed by casting or press-forming, the face is formed by press-forming, and these are joined together by welding. The metallic material used is selected from a steel material group of martensite deposition hardening-type stainless steel, maraging steel, and maraging stainless steel. Only a material having a specific gravity of 7.7 or higher is used, and the head body has a volume of 280-320 cc and a weight of 180-205 g. The golf club head enables increasing the meet rate, has design freedom, exhibits excellent processability, and can be manufactured at a low cost.

Abstract: A face portion 11 of a golf club head 10 is obtained press-forming a metal plate into a predetermined shape. On the front surface 11a of the face portion 11, score lines 12 are formed by means of die sinking of electrical discharge machining, and a mirror finished surface portion 13 is formed by means of finish processing of electrical discharge machining. On the rear surface 11b of the face portion 11, a rib structure 15, and a high hardness layer 16 of an amorphous metal layer are formed. The electrical discharge machining is numerically controlled.

Abstract: A hollow golf club head made of a metallic material. The golf club head has a three piece structure of a main head body, face and crown. The main head body and the crown are formed by casting or press-forming, the face is formed by press-forming, and these are joined together by welding. The metallic material used is selected from a steel material group of martensite deposition hardening-type stainless steel, maraging steel, and maraging stainless steel. Only a material having a specific gravity of 7.07 or higher is used, and the head body has a volume of 280-320 cc and a weight of 180-205 g. The golf club head enables increasing the meet rate, has design freedom, exhibits excellent processability, and can be manufactured at a low cost.

Abstract: A golf club head 10 includes a crown portion 11, a face portion 12, a side portion 13 a back face portion 14, and a neck portion 15. The crown portion 11 has a protruded portion in which a maximum point P of a curved contour of a central cross section (X—X line) of the crown portion is positioned rearwardly of the center I of the golf club head, and a cut-away portion obtained by obliquely cutting off the rear peripheral portion thereof. A volume V2 of a back-face-portion-side portion of the golf club head, which is positioned rearwardly of the head center I, is greater than a volume V2 of a face-portion-side portion of the golf club head, which is positioned in front of the head center I.