After two boring machines (a by Bosch, with Plastikbohrfutter) had tried at hinges of a barn, drill out old 8-holes on 12-holes and did not succeed because of the slipping drill, I have invested the money and made me this Qualitätsbohrfutter. This is made of metal, you can fix the drill easily with little effort and then stops even with a high torque without slipping. I then can drill playing with my big hammer the 12er holes. Given the time that I had already invested, the chuck is a bargain.
