I'm glad that you discovered Unibits, Dana. They should probably be in each of our tool kits. In metal they are the only bit I've found that will cut a perfectly round hole. Then, if you just allow the next ring to just touch the metal it will deburr and give you a slight bevel.

One warning I'd like to provide; accept no substitutes. Milwaukee and Craftsman both make Unibit look-alikes. Unibit is the only one that has the single flute design. I believe that they have a patent on that feature. It's the single flute design that makes the perfectly round holes. The others have multiple flutes and don't work as well.

Be sure to get the actual Unibit and not an imitation.

Bill Harrelson
5zq@cox.net
N5ZQ  320  900 hrs
N6ZQ   IV   1.02%