Abstract: A mounting bolt for a sub-frame is disclosed. A mounting bolt for a sub-frame that is configured to a sub-frame to a front side member of a vehicle according to one or a plurality of exemplary embodiments of the present invention may include a bolt body that is inserted into a through-hole of a mounting bracket that is fixed to the front side member and joined to the mounting bracket through a head portion, and a support body that has a cylindrical shape, is friction-welded to a center of an upper surface of a head portion of the bolt body along one line, and of which an upper end is joined to the front side member.

Abstract: A mounting bolt for a sub-frame is disclosed. A mounting bolt for a sub-frame that is configured to a sub-frame to a front side member of a vehicle according to one or a plurality of exemplary embodiments of the present invention may include a bolt body that is inserted into a through-hole of a mounting bracket that is fixed to the front side member and joined to the mounting bracket through a head portion, and a support body that has a cylindrical shape, is friction-welded to a center of an upper surface of a head portion of the bolt body along one line, and of which an upper end is joined to the front side member.

Abstract: A vibration spot welding device according to an exemplary embodiment of the present invention may include a first welding tip that is disposed to contact one side surface of metal plates that are overlapped, and a second welding tip that is disposed to contact the other side surface of the metal plates corresponding to the first welding tip, wherein the second welding tip includes a first electrode portion that is disposed to contact the metal plate so as to transmit a current thereto, and a second electrode portion that is disposed to contact the metal plate so as to receive the current that is transferred from the first electrode portion through the metal plate.