Since we've got all these experts on board, I won't try to share 50-something years' worth of experience doing precision work on brakes. I do have two drum micrometers for a reason, I own a disc/drum lathe, and I've generated several hundred pounds of cast iron shavings with a drum lathe, though!
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!