The 3/16" - 1/2" diameter Viking Type 78-UB #00701 Ultra Bit Multi-Diameter Step Drill Bit has a unique dual flute design for cutting fast, clean holes that are accurate and burr-free. The enhanced flute design also rapidly removes chips, ensuring a longer bit life and reducing the possibility of binding. The split point on the tip of the Ultra-Bit is designed for faster penetration and prevents walking. The unique Gold Oxide coating reduces friction and heat for a smoother cut and helps extend the life of the tool. Ultra-Bit Step Drill bits feature a round shank with 3-Flats for a secure grip when used in drills with standard 3-jaw Jacob style chucks.