Starrett A1 Arbor & High Speed Steel Pilot Drill Bit For 14-30mm Hole Saws The Starrett A1 Arbor with 6.35mm (1/4\") high speed steel pilot drill and 8.75mm (11/32\") hex shank fits hole saw diameters 14-30mm (9/16\" - 1.3/16\"). A set screw in the body allows for easy replacement of the pilot drill. Screw thread 1/2\" - 20. FEATURES Compatible with hole saws of diameters from 14-30mm, including the FCH0100 and FCH2532 Fitted with a 6.5mm / 1/4\" pilot drill Set screw in arbor body allows easy replacement of the pilot drill SPECIFICATION Pack Quantity: x1 Pc Part No: A1 Diameter / Shank Size: 8.75mm PTA Shank Type: Hex Shank