Premium Holesaw Arbor, the best option for all Dart holesaws and will also fit most other holesaws available. This arbor has a unique thread allowing two holesaws to be mounted inside each other, so that holes can be enlarged with ease. Supplied with our standard 83mm long pilot drill, which can also be interchanged with the other holesaw pilot drills available from our range. This arbor has a 11mm Hex shank, and can be used on holesaws from 32 to 210mm