This drill is the new HSS Steel Large Step Cone Drill Bit Set Cutter Titanium Hole, which is made of high quality HSS steel and coated with titanium to reduce friction and heat. It is very suitable for drilling holes in a variety of materials including steel, brass, wood, plastic, etc. Made of M42 to high speed steel with a titanium coating to reduce friction and heat .< /li> No pilot holes or pre-drilling required. Automatically deburrs holes when drilling. Best for thin metals, steel, aluminum, copper, brass, fiberglass, PVC, etc. Product Description Unique step design This drill can be used to open holes of different sizes, i.e. the equivalent of a box of drills. which are designed to precisely drill holes of different sizes from 4mm to 32mm in diameter, with optimal speed and precision. Easily identify the size you need using the contrasting laser-etched sizes in the drill groove. HSS and Titanium Coated Our step drill bits are made from super strong HSS steel and coated with