compressing {TAIL ~ the protruding end} of the hollow tubular heat pipe via the pointed extruding shaft to render the protruding end of {HEAD ~ the heat pipe} to be depressed inward into inside of the hollow tubular heat pipe, thereby obtaining the hollow tubular heat pipe having a concaved end surface 
compressing { TAIL ~ the protruding end } of the hollow tubular heat pipe via the pointed extruding shaft to render the protruding end of { HEAD ~ the heat pipe } to be depressed inward into inside of the hollow tubular heat pipe , thereby obtaining the hollow tubular heat pipe having a concaved end surface
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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