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 3/16 in, Fits Hole Saw Dia. – Metric 14 to 30 mm, Includes Pilot Bit Pilot Bit Included, Pilot Bit Size 1/4 in, Pilot Bit Shank Style Hex, Pilot Bit Shank Size 1/4 in, Pilot Bit Overall Length 3 1/4 in, Pilot Bit Material High Speed Steel