Hole Saw Arbor, Arbor Type Quick Change, Thread Size 1/2 In.-20, Arbor Shank Style Hex, Arbor Shank Size 3/8 in, Fits Hole Saw Dia. - Imperial 9/16 in to 1 1/4 in, Fits Hole Saw Dia. - Metric 14 to 32 mm, Includes Pilot Bit Pilot Bit Included, Pilot Bit Shank Style Hex, Pilot Bit Shank Size 3/8 in, Pilot Bit Material High Speed Steel.