The g j halls conecut is a versatile hole cutting tool for rapid drilling and enlarging holes in thin materials up to 2mm thick designed for industrial applications the diameter of the hole increases as the conecut is advanced into the material providing infinitely variable sizes for use in sheet steel non ferrous metals plastics formica and plywood the conical shape of the tool enables any size of hole to be drilled between the bottom and the top of the taper when drilling metals always use