I used this attachment in my plunge milling machine to "hollow out" a couple of discs to be glued into the shell blank. This drill will cut a nice clean edge in thick wood. In the photo cherry 6/4, maple 4/4 and sapele 4/4. Of course I did this in multiple passes, but I ended up with a nice clean, sharp edge. I never give 5 stars. And at the end of the cut, the bit looks new on 6 of those discs.