BLOSTM Stepped Drill Bit Set - 3pcs High Speed Cone Cutter HSS Drill Bit Set Includes 4-12mm, 4-20mm & 4-32mm - Step Drill Bit for Metal Sheet, Wood - 3 PACK Cone Cutter Set Drilling holes is a breeze with this HSS steel high-speed step drill bits set! This toolkit includes sizes 4-12 mm, 4-20 mm, and 4-32 mm for a wide range of professional and DIY applications. You can efficiently process copper, aluminum, steel, cast iron, PVC, wood, and more!