I cut several 1/2" deep channels in the spruce wood surface. A locally purchased Freud drill bit cut through like butter but broke in half fairly quickly, which is what they are prone to. I chose to after hearing all the good reviews. The bottom line is this thing cut like the blade had never been sharpened, even at slower router speed and very slow movement it would get stuck and refuse to move forward or decide for no reason, jumping out of the cut. He won't even try to cut the knot, even approach it at a snail's pace. Let's go back to Freud, I think, and risk tearing it apart again.