Ed, if you had not told me, how would I know? A millimeter here, a millimeter there, who's going to get all over that?? Looks like a good job to me. As to hole saws, there are hole saws and then there are bi-metal hole saws, so I learned just the other day. Bi-metal teeth seem to work much better. Also, using a new one is the ticket too. Had to drill a 4-1/8 in. hole through a double 2x10 band plate to vent a dryer. Use new saw, drill pilot first, go slow. Let the tool do the work. All will be good.