A method of making a golf club head includes the steps of: preparing a head body including a front engaging face, a back face, an opening extending through the front engaging face and the back face, a groove extending around the opening and recessed inwardly from the front engaging face, a peripheral edge surrounding the groove, and at least one flange extending along the peripheral edge and protruding away from the front engaging face; mounting a striking plate on the front engaging face to cover the opening; bending the flange toward the striking plate and pressing the flange against the striking plate; joining the striking plate to the head body using a solder; and polishing the head body and the striking plate to remove excess of the flange and the solder.