MandreX Ultimate SpeedXbit 8 Pcs Kit 10, 12, 16, 18, 20, 25, 28, 32mm Extreme fast drilling of holes compared to conventional flat spade drill bits. Our unique self-feeding threaded QuickTip Technology enables the drill bit to effortless pull itself into the wood. Precision grounded cutting edges for faster drilling and longer life time and a black oxide finish for more durability. Suitable for use on soft and hard wood, light building materials and plasterboard. This spade bit has a 1/4-inch hex shank and can be used in electric battery powered & cordless power tools, including impact drivers. FEATURES - Widest range of wood & wooden materials - Extremely fast because of the self-feeding QuickTip technology - Cutting depth 152 or 406mm - Hex 1/4-inch powerbit shank - Highest grade hardened steel cutting edges - Suitable for use in electric & battery powered tools