Heavy Duty Drill Sets: high speed drill sets are made with M-7 high speed steel. The 135° angle of the tip allows more of the cutting edge to be in contact with the material. The split point self centers the drill bit keeping it from "Walking" across the surface. These self-centering, premium grade, high speed drill bits will outlast and out perform general purpose high speed bits commonly sold in our industry. Ideal for cutting hard, tough materials.