Read the original post- - - - -he's working with a 1/2" NPT TAPRED PIPE THREAD TAP! The bushing he's trying to install isn't threading into the hole he's tapped far enough, and apparently it's bottoming out against something. Grinding off a few of the starting threads of ther tap (THE NARROW END OF THE TAPER!) will allow the TAPER THREADED BUSHING to screw in deeper!
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!