{HEAD ~ The conical sections} are either stepped or smooth for {TAIL ~ different force loadings} particularly in the application of different types of closures thereto 
are stepped for
{ HEAD ~ The conical sections } are either stepped or smooth for { TAIL ~ different force loadings } particularly in the application of different types of closures thereto
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH REL OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH