This Milwaukee® hole saw arbor has a 3/8 in hex shank for greater gripping capability in the chuck. It can be used in 3/8 in capacity drills and larger. The arbor has a 1/2-20 thread and can be used on hole saws from 9/16 to 1-3/16 in it can be used with 49-56-8010 pilot bit which is supplied with this arbor for use on wood and metal. Milwaukee® 49-56-7010 Small Thread Hole Saw Arbor, Up to 1-3/16 in Arbor, 3/8 in, Hardened Steel