Impact Pro Screwdriving Bits Made From Heat Treated Premium Grade Steel To Ensure Optimal Performance In All Applications. Century's Patented Heat Treatment Process Provides Maximum Shock Absorption Associated With Impact Ready Power Tools. Precision Ground Tips For Maximum Contract And Secure Grip. Meets Anis Specifications. Black Oxide Coating Resists Corrosion And Signifies That The Accessory Is Impact Rated. For Use In Standard And Cordless Impact Drivers.