55142 Shank Size Symbol: 7/16 in. Hex (part# 55142) This item features: -With 1/4" high speed steel pilot drill. -Set-screw in the body allows easy pilot drill replacement. -Permits instant change of hole saw blades without tools and without removing the arbor from the chuck. -Fits 1/2" chuck size. -Fits 3/8" chuck size. -Type: Arbor. -Price is for 1 Each.