Arbor A ~ Suitable for use with hole saws between 14-30mm. Arbor A has a 1/4 round shank. Arbor B ~ Suitable for use with hole saws between 14-30mm. Arbor B has a 3/8 hex shank. Arbor C ~ Suitable for use with hole saws between 32-177mm. Arbor C has a 7/16 hex shank. Note: All Arbors include a pilot drill. We also have extra pilot drills available for purchase below. View Product