Hole saw arbors with SDS as well as hexagonal shank are tted with a fully ground pilot drill. The drill is xed with a grub screw (M8). The way to fix the hole saw on the arbor is depend on the size of hole saw. The smaller sizes are fixed with an open end spanner (14-30 mm). The wrench sizes varies between 16-26 mm. Bigger hole saws have 2 or 4 holes for the arbor tang. The fixation ring avoid to slipper by using.