Diablo's new Step Drill Bits bring exclusive technology to the Electrician， Plumber and HVAC contractor with fast， accurate cuts and increased stability in thin metals， PVC other plastic materials. The innovative Split Point Tip design enables a fast， on-point start resulting in increased durability and up to 6X longer life. An automated precision grinding process on each step reduces wear and delivers 2X faster cuts. Multiple hole sizes are made easy with laser etched step markings while increased step heights for common hole sizes makes drilling holes more efficient and faster. Designed with a 1/4" hex shank， these bits are impact ready and can be used with drills and impact drivers.