I bought these and used them about 5-6 times to round off some MDF and plywood edges. You did your job. I can't get 2 big ones to go through my cobalt router base. I saw a video of someone making a large plexiglass base for more stability and he said the large cutters should not be used on small edge routers as it could burn out the motor. More power is required to turn and cut with larger cutting tools. This may be why the two big bits aren't going through my router base. Just had to buy a smaller 3/8" bit instead of a 5 bit kit.