The Grainger 20-piece Threaded Shank Drill Bit Set features high-speed steel construction with black oxide finish. The set includes sizes ranging from 1/16 inch to 1/2 inch by 64ths. The 135-degree split point tips provide fast, accurate starts and reduced walking. The bits have a straight shank and 1/4 inch hex drive end to fit power drills. Made in the USA, this drill bit set is designed for use on metal, wood, and plastic. The set comes packaged in a plastic index case for storage and organization.