Have a Indestro socket set which contains one oddball socket. It has a conical internal knurled surface. Can someone give me use of this socket ? This is 1/4 hex drive set. Driver is stamped(Indestro Mfg Corp Chicago Pat pend) Anyone have approx date on manufacture ? Can't seem to include picture as error message says file too large even with only one photo. Maybe someone will recognize usage from description till I find what I'm doing wrong.