Superior to Bi-Metal Holesaws! Faster and More Accurate Drilling. Longer Tool Life. For use in an electric drill: Ideal for drilling steel plate, stainless steel, iron, aluminum, copper, cast iron, fiberglass and plastics up to 1 inch thick Unique Triple Edge Cutting System for fast, bur free/smooth drilling Ejector spring ejects slug saving time and safety collar stop prevents over penetration for safer, faster operation Common applications include drilling: junction/switch boxes, metal studs, appliances, auto body repair, truck/trailer frames, ductile pipe