This Milwaukee hole saw arbor has a 7/16 in. hex shank for greater gripping capability in the chuck. It can be used in 1/2 in. capacity drills and larger. The arbor has a 1/2 - 20 thread and can be used on hole saws from 9/16 in. to 1-3/16 in.. it can be used with 49-56-8000, 49-56-8002 and 49-56-80