I bought these for my recently purchased Trim Router. I needed this set mainly because of the variety of round nozzles I use to trim the edges of children's wooden toys. After about 20 minutes of rounds, my 1/8" drill fell apart and spilled metal and debris everywhere. Upon further inspection, the bearing was seized, had somehow fallen out of the drill and caught the carbide blades and got everywhere Luckily I wasn't hurt (yes I was wearing protective gear) I was hoping these bits would last more than 20 minutes but maybe I should lower my expectations These bits are good for occasional use and should be cleaned thoroughly but not for intensive work.