Greenlee 645-001 &frac14; Inches x 2-1/2 Inch Pilot Drill used with Sizes 5/8-Inch Diameter Through 2-1/4 Inches Diameter Hole Cutters Cuts stainless steel quickly and easily Quick change arbor allows you to change cutter heads with a simple push and a turn Use the same arbor for different size cutting heads Flange stop prevents over-drilling Replaceable, cobalt-steel pilot drill with split-point tip to prevent walking Item dimensions are  Inches diameter x 2-1/2 Inches overall length