Not really. At least not for brass or aluminum. Since the pin jaws have a slight taper on the inside there isn't quite as much contact with metal as there would be on wood but so far that hasn't been a problem. I have to be a little more careful that the drill bits don't catch when boring the holes for the tubes. I use the reamer to align the blank in the chuck when I'm milling the ends of the blanks. Also, I TBC rather than use the mandrel.