Spring Loaded Pilot 11,000 Series 5/16" 3X faster than twist drills or hole saws in sheet metal, plate and plastics up to 1/2" thick. Heat treated and precision ground tools can be used in hand held drills with chucks having 3/8" capacity or greater. Proven to cut round holes faster, virtually burr-free and with longer tool life than conventional tooling. 14,000 series 7/8" thru 2-1/2" Hole Cutters cut rather than tearing and deforming the stock as do typical hole saws, and have a spring loaded arbor system for quick slug ejection.