Golf club head and method for manufacturing the same

1. A method for manufacturing a golf club head having a hollow structure composed of a main body-member and a metal face member welded to the main body-member, the metal face member integrally including a face-plate and a turnback, the face-plate having a rear surface and a front surface forming a club face, the face-plate comprising a central thick part and a thinner peripheral part therearound, and the turnback extending backward from at least part of the edge of the club face, the method comprising:

step (a) of preparing a rolled material having a constant thickness;

step (b) of cutting out a face member part from the rolled material;

step (c) of making the face member by forming the turnback through press working on the face member part; and

step (d) of machining the cutout face member part after the step (b) and prior to the step (c) to reduce the thickness of a corresponding-to-turnback region and a part of a corresponding-to-face-plate region,

wherein the corresponding-to-turnback region is a region of the cutout face member part corresponding to the turnback, and the part of the corresponding-to-face-plate region is a region of the cutout face member part corresponding to the thinner peripheral part of the face-plate,

wherein the machining is carried out on a flat surface of the cutout face member part corresponding to the rear surface of the face-plate, and

wherein, the method further comprises, prior to the step (c), a step of heat treating the cutout face member part by heating the cutout face member part in a temperature ranging between 700 and 800° C., for 30 to 60 minutes and then slowly cooling down.

2. The method according to claim 1 , wherein

the turnback is formed along the substantially entire length of the edge of the face-plate.

3. The method according to claim 2 , wherein

the turnback includes a crown-side turnback, a sole-side turnback, a toe-side turnback and a heel-side turnback, and

each of the maximum length of the toe-side turnback and the maximum length of the heel-side turnback is not more than 50% of the maximum length of the crown-side turnback and not more than 50% of the maximum length of the sole-side turnback.

4. The method according to claim 1 , wherein

the rolled material is multidirectionally rolled in at least two different rolling directions, the intersecting angle between which is in a range of from 70 to 90 degrees.

5. The method according to claim 1 , wherein

the thickness of the face-plate is not less than 3.0 mm, and

the thickness of the turnback is not more than 2.0 mm.

6. The method according to claim 1 , wherein in the step (b), a plural number of the face member parts are cut out from the rolled material.

7. A method for manufacturing a golf club head having a hollow structure composed of a main body-member and a metal face member welded to the main body-member, the metal face member integrally including a face-plate and a turnback, the face-plate having a rear surface and a front surface forming a club face, the face-plate comprising a central thick part and a thinner peripheral part therearound, and the turnback extending backward from at least part of the edge of the club face, the method comprising:

step (a) of preparing a rolled material having a constant thickness;

step (b) of cutting out a face member part from the rolled material;

step (c) of making the face member by forming the turnback through press working on the face member part; and

step (d) of machining the rolled material prior to the step (b) to reduce the thickness of a corresponding-to-turnback region and a part of a corresponding-to-face-plate region,

wherein the corresponding-to-turnback region is a region of the rolled material corresponding to the turnback, and the part of the corresponding-to-face-plate region is a region of the rolled material corresponding to the thinner peripheral part of the face-plate,

wherein the machining is carried out on a flat surface of the rolled material corresponding to the rear surface of the face-plate, and

wherein, the method further comprises, prior to the step (c), a step of heat treating the cutout face member part by heating the cutout face member part in a temperature ranging between 700 and 800° C., for 30 to 60 minutes and then slowly cooling down.

8. The method according to claim 7 , wherein the turnback is formed along the substantially entire length of the edge of the face-plate.

9. The method according to claim 8 , wherein

the turnback includes a crown-side turnback, a sole-side turnback, a toe-side turnback and a heel-side turnback, and

each of the maximum length of the toe-side turnback and the maximum length of the heel-side turnback is not more than 50% of the maximum length of the crown-side turnback and not more than 50% of the maximum length of the sole-side turnback.

10. The method according to claim 7 , wherein the rolled material is multidirectionally rolled in at least two different rolling directions, the intersecting angle between which is in a range of from 70 to 90 degrees.

11. The method according to claim 7 , wherein

the thickness of the central thick part of the face-plate is not less than 3.0 mm, and

the thickness of the turnback is not more than 2.0 mm.

12. The method according to claim 7 , wherein in the step (b), a plural number of the face member parts are cut out from the rolled material.