The plug is further provided with {TAIL ~ an axial passage way} 18 communicating with the hexagonal square or circular wrench end of the plug at {HEAD ~ one end} and terminating adjacent to and just short of the threaded end 
The plug is further provided with { TAIL ~ an axial passage way } 18 communicating with the hexagonal square or circular wrench end of the plug at { HEAD ~ one end } and terminating adjacent to and just short of the threaded end
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH