The Bosch IMD5007 is a Black Oxide Hex Shank Impact Tough Drill Bit Set. They have a speed helix design for three times faster drilling than standard bits. These bits last 50% longer than high-speed steel. They They allow easier drilling, reduced heat and extended drill bit life Available in jobber length, stubby length, extended length (aircraft), 1/2 In. reduced shank (Silver and Deming).