Hole Saw Arbor, Arbor Type Standard, Thread Size 1/2 In.-20, Arbor Shank Style Round with Flats, Arbor Shank Size 1/4 in, Fits Hole Saw Dia. - Imperial 9/16 in to 1 3/16 in, Fits Hole Saw Dia. - Metric 14.3 to 30.2 mm, Includes Pilot Bit Pilot Bit Included, Pilot Bit Shank Style Round, Pilot Bit Shank Size 5/16 in