Inton M35 USA Cobalt Coated Step Drill Bit Set, 34 Sizes | 3-piece Set REPLACES 34 DRILL BITS: This set includes three standard SAE step drill bits that replace 34 individual drill bits USA COBALT COATED STRENGTH: Made of super strong M35 steel with cobalt coating for added durability and bit life SMOOTH DRILLING ACTION: Two-flute design provides faster, smoother cutting without walking and a tri-flat shank ensure a firm grip PROFESSION TO DRILL SS: one 3-13mm to thirteen-step bit,6-25mm ten-step bit, and 6-35mm eleven-step bit CUTS AND DEBURRS: Cuts through steel plate, Stainless Steel plate and other surfaces,high-efficient and Durable