Carbide tipped hole cutters are used to cut holes in metal and other materials. Cutting tools having this annular design only remove the material around the circumference of the tool. Because all of the material is not removed in the drilling prcoess, holes can be cut much faster than using twist drills, and a solid slug is ejected after the cutting operation. Carbide teeth ensure efficint cutting and long tool life in a variety of materials. The CT5 hole cutter will cut through thin metals, fiberglass and plastics up to 3/16" thick. It's one piece construction, ejector spring and safety collar stop make this the perfect portable tool for electricians, plumbers, mechanics and contractors. Diameters 9/16" through 1" have a 3/8" (10mm) shank.