{HEAD ~ The head pipe} has a supporting surface portion corresponding to the surface of {TAIL ~ the aforementioned warped intermediate portion} 
{ HEAD ~ The head pipe } has a supporting surface portion corresponding to the surface of { TAIL ~ the aforementioned warped intermediate portion }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL