These extra-strong bits are designed specifically for use in the impact tools used by automobile, aircraft, mobile home, and other demanding manufacturers. The bits are machined from one piece of steel, then carefully hardened to make sure that the driver tip can take the expected abuse without shattering. In addition, the hardened steel bodies are less susceptible to distortion which can make removal of our two-piece bits difficult. We highly recommend these bits for use in cordless impact tools with 1/4” hex chucks. All bits are standard 1/4” hex shank, and made in USA.