Golf club head with removable weight

1. A golf club head comprising: a head body including a recess portion for a socket; a socket attached to the recess portion for a socket; and a weight body detachably attached to the socket, wherein

the weight body can be secured by relative rotation of an angle +θ° to the socket;

the secured weight body can be detached by relative rotation of an angle −θ° to the socket;

the weight body includes an engaging portion for engaging the socket, wherein a distance between a central point and a point farthest from the central point in an outline of a section of the engaging portion is defined as R 1 , a distance between a central point and a point nearest to the central point in an outline of a section of the engaging portion is defined as R 2 , and the ratio R 1 :R 2 ranges from 1.30 through 1.70 inclusive;

the socket includes a first hole and a second hole positioned on a deeper side than the first hole, wherein

said second hole includes a reverse rotation suppressing portion which protrudes inwardly, configured such that engaging portion distance R 1 and a maximum height of the reverse rotation suppressing portion R 3 have a ratio R 3 :R 1 equal to or greater than 0.19, and

said second hole includes an excess rotation suppressing portion which protrudes inwardly, configured such that engaging portion distance R 1 and a maximum height of the excess rotation suppressing portion R 4 have a ratio R 4 :R 1 equal to or greater than 0.19;

the engaging portion is movable into an engaging position EP and a non-engaging position NP at the second hole;

assuming that rotation of the weight body is rotation about an axis line Z, the engaging portion has a sectional shape with N-fold rotation symmetry with the axis line Z as a rotation axis, wherein N-fold rotation symmetry signifies that a cross-sectional shape after being rotated by 360/N degrees about a rotation axis coincides with the cross-sectional shape before such rotation; and the maximum value of N is 1, 2, or 3.

2. The golf club head according to claim 1 , wherein the maximum value of N is 2.

3. The golf club head according to claim 2 , wherein the sectional shape of the engaging portion is substantially rectangular.

4. The golf club head according to claim 1 , wherein

the recess portion for a socket includes an undercut portion;

the socket includes an engaging projection portion; and

the undercut portion and the engaging projection portion are engaged with each other.

5. The golf club head according to claim 4 , wherein

the recess portion for a socket includes a polygonal inner surface, and

the undercut portion is provided on the polygonal inner surface.

6. The golf club head according to claim 4 , wherein

the socket includes a wall portion;

the wall portion forms an upper end portion of the socket; and

the wall portion includes the engaging projection portion.

7. The golf club head according to claim 6 , wherein the wall portion includes an aperture.

8. The golf club head according to claim 6 , wherein if an engaging width between the undercut portion and the engaging projection portion is defined as W 1 , and a clearance distance between the wall portion and the weight body is defined as W 2 , the clearance distance W 2 is less than the engaging width W 1 .

9. The golf club head according to claim 8 , wherein the engaging width W 1 ranges from 0.2 mm through 1.0 mm inclusive.

10. The golf club head according to claim 3 , wherein the rectangle is not a square.