{HEAD ~ A rotatable fastener} has {TAIL ~ a head portion} with an axially facing ring gear engageable with a complementary gear of a drive tool 
{ HEAD ~ A rotatable fastener } has { TAIL ~ a head portion } with an axially facing ring gear engageable with a complementary gear of a drive tool
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH