This drill bit is the new HSS Steel Large Step Cone Drill Bit Set Cutter Titanium Hole, which is made from high quality HSS steel, and with titanium coated to reduce friction and heat It is very suitable to use for drilling holes in a variety of materials, including steel, brass, wood, plastic, etc. Made from high speed M42 steel with a titanium coating to reduce friction and heat. No pilot holes or pre-drilling required. Automatically deburr holes as you drill. Best for thin metals, steel, aluminum, copper, brass, fiberglass, PVC, etc. Unique step design This drill bit can be used to open holes of various sizes, that is, the equivalent of a bit box. which are designed to precisely drill holes of various sizes, from 4mm to 32mm in diameter, with optimum speed and precision. Easily identify the size you need with the contrasting laser-etched sizes inside the bit flute.