I bought this to cut 2 3/4" deep grooves in hard maple leaf (Split Top Roubo project). I had no problem getting to that depth (even with a 1/4" MDF stencil) and cut his work without complaining. At full depth care should be taken to make easy passes. For the grooves, I went straight down the corners first and then did easy full depth passes around the circle. After seeing that it worked I bought three more bits in case they went missing. It's hard to find the length and I was pleasantly surprised to see it work well.