Hole Saw Arbor, Arbor Type Standard, Thread Size 1/2 In.-20, Arbor Shank Style Hex, 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 to 30 mm, Includes Pilot Bit Pilot Bit Included, Pilot Bit Shank Style Hex, Pilot Bit Shank Size 1/4 in