A head body h1 includes a recess part 14 for a socket. A socket 10 is attached to the recess part 14 for a socket. A weight body 12 is detachably attached to the socket 10. The weight body 12 can be secured by relative rotation of an angle +θ°. The weight body 12 can be detached by relative rotation of an angle−θ°. The weight body 12 includes an engaging part 32. The socket 10 includes a first hole part 18 and a second hole part 20. The engaging part 32 can take an engaging position EP and a non-engaging position NP at the second hole part 20 by the relative rotations. A sectional shape of the engaging part 32 has N-fold rotation symmetry. N is an integer of 1 or greater and 3 or less.