Drill America gold Stepped Point Cobalt Drill Bits start easier, drill faster, increase lifespan and reduce heat compared to standard drill bits. They can be used to enlarge existing holes or to create new, smoother holes in a wide range of materials such as acrylics, steel, metal, brass and other hard metals. These drills have a 135 degree split point tip and a 3 -flat shank to prevent spinning. Sizes in set: 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm. Comes in plastic pouch case.