{TAIL ~ an extrudate member} having {HEAD ~ a closed sectional structure portion} and at an end thereof in the extruding direction, an integral joining end; and 
{ TAIL ~ an extrudate member } having { HEAD ~ a closed sectional structure portion } and at an end thereof in the extruding direction , an integral joining end ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH