This is a great drill bit, but it didn't work for me because I needed to drill three parallel slots in a 1-1/2 inch ledge and the router bit setting didn't work. not set high enough to do what I need. It's not her fault, just my short-sightedness. But if you have a similar need (the grooves aren't close to the bottom edge of your butt) this bit won't work. I ended up using a 45 degree oblique drill to cut the grooves with the butt on the end edge. It wasn't as good as it could have been, but it worked well.