I made a cherry table and used it to cut the grooves and the grooves were 6 boards long. I made grooves 1/2" deep for the slots to position the boards. Total cutting distance is about 55 feet of cut. The drill bit was still sharp and cut 10 1 3/4" deep slots in the ends of the table I think there's a chance those who broke the drills tried to cut all the way through in one pass and at too high a speed. . To cut a full 1 3/4" groove, I did 3 passes, which is more or less standard procedure. Using digital calipers, I checked the floating studs that fit the grooves and they measured .373"..375's 3/8 inch.