[Tim Baird]

I've actually done this same thing but to make a knurled surface.

Grind off all but one flute, put the tap into a vertical mill and make a pass on your piece (cutting along the side, obviously). Rotate the piece 90 degrees in your vice, and make a pass again. It'll leave you with a nice knurled face that's good for gripper jaws on end-effectors.