Golf club head

1. A hollow wood-type golf club head comprising:

a face portion whose front face defines a club face for hitting a ball,

a crown portion intersecting the club face at the upper edge thereof,

a sole portion intersecting the club face at the lower edge thereof, and

a side portion that is between the crown portion and the sole portion which extends from a toe-side edge to a heel-side edge of the club face through a back face of the club head, wherein

a head volume is not less than 400 cm 3 ,

a head weight is in the range of from 170 to 200 g,

a coefficient of restitution of the club head is not less than 0.800, and less than 0.830,

a thickness of the club face at the sweet spot is in the range of from 2.9 to 3.2 mm,

a depth of center of gravity of the club head is in the range of from 35.5 to 43.0 mm and

a moment of inertia around a vertical axis passing through a center of gravity of the club head under a standard condition that the club head is set on a horizontal plane while keeping its lie angle and loft angle is not less than 4100 g·cm 2 and not more than 5700 g·cm 2 ,

the head comprises a face component including a major part of the club face and a head main body being welded to the face component to form the club head and having a hosel with an insertion hole to be attached to a club shaft,

the face component has the face portion and a turnback which extends backward from the edge of the club face to form a part of the crown portion, sole portion and each side portion,

the face portion comprises

a center portion which has a thickness t 1 and an area including the sweet spot,

a periphery portion being provided around the center portion and having a thickness t 2 smaller than the thickness t 1 of the center portion and

a transit portion connecting between the center portion and the periphery portion with a thickness gradually changing from the thickness t 1 to the thickness t 2 ,

the thickness t 1 of the center portion is not less than 2.90 mm and the entire periphery has a thickness t 2 of not more than 2.60 mm,

the turnback is formed by methods of bending, a casting process, or a forging except welding,

the face component is provided with a dent portion at a position corresponding to the hosel of the head main body,

the head main body is made of a metal material,

the head main body comprises the hosel, a major part of the crown portion, a major part of the sole portion, a major part of the side portion and a front opening which is closed with the face component,

the face component consists of a high-strength part made of a titanium alloy whose tensile strength is in the range of 950 to 2200 MPa, and

the high-strength part has a Young's modulus in the range of from 120 to 160 GPa, wherein the titanium alloy consists of, in weight %, Al: 3.5-5.0%, Fe: 0.1-2.0%, and the balance of Ti and at least one inevitable impurity.

2. The golf club head according to claim 1 , wherein the titanium alloy contains Al of not less than 4.0%.

3. The golf club head according to claim 1 , wherein the titanium alloy contains Fe of not less than 0.5%.

4. The golf club head according to claim 1 , wherein the high-strength part comprises a forged titanium alloy.

5. The golf club head according to claim 1 , wherein the Young's modulus of the high-strength part is not less than 130 GPa.

6. The golf club head according to claim 1 , wherein the Young's modulus of the high-strength part is not less than 135 GPa.

7. The golf club head according to claim 1 , wherein the tensile strength of the high-strength part is not less than 1300 MPa.

8. The golf club head according to claim 1 , wherein a welded portion between the face component and the head main body is located backward apart from the edge of the club face.

9. The golf club head according to claim 1 , wherein a length of the turnback portion in a front-back direction is in a range of 7 to 30 mm.