The operation for coupling the metallic parts only needs to nip {HEAD ~ the flanges} 17 and 27 of {TAIL ~ the metallic parts} 11 and 21 with the fingers and bring the metallic parts 11 and 21 close to each other 
The operation for coupling the metallic parts only needs to nip { HEAD ~ the flanges } 17 and 27 of { TAIL ~ the metallic parts } 11 and 21 with the fingers and bring the metallic parts 11 and 21 close to each other
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH