It is another object of the present invention to provide a joining method of the type described above, wherein the need for a joining jig which is required in {HEAD ~ use} of {TAIL ~ a butt welding joint} is eliminated to provide an improved joining operatability 
of
It is another object of the present invention to provide a joining method of the type described above , wherein the need for a joining jig which is required in { HEAD ~ use } of { TAIL ~ a butt welding joint } is eliminated to provide an improved joining operatability
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH