Google "1/2" inverted flare female" fitting. I'll bet that's what you have. The male fitting that works with it is the same kind you see on pre-made steel fuel lines- - - -a much bigger version of the same thing that's on a steel brake line.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!