The CaRoller drill bits sets are an excellent choice for professionals as well as DIY enthusiasts, enjoying superior durability and including various sizes that go well with your multiple needs. Made with heavy duty cobalt steel, with a self-centering 135-degree split point which produces smaller chips and smoothly penetrates materials, these drill bits for metal ensure precision and accuracy, successfully cutting hardened metals such as stainless steel, cast iron, high temperature alloy, titanium alloy, hard plastics and wood!