DEWALT DWADTQTR3816 Impact Ready® 16 UNC Drill Tap 1/4" Capacity features a 1/4" hex shank for use in impact drivers. This item allows you to drill, tap, and countersink all in one step; capable of working with up to 1/4" thick material capacity. Commonly used by Elevator Installers, Mechanicals, Electricians, Glaziers.