Material: Titanium Coated 4241 (HSS) High Speed Steel. This set of three cone drill bits is very well constructed and allows you to arrive at the desired drilling diameter without changing drill bits several times. br/> Depending on the need to process holes of different diameters, disposable macroprocessing can be achieved without having to replace the drill bit and position the holes. 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. Ideal for a wide range of materials, openings and openings bore, including metals, aluminum, wood, plastics and more. It can be used for thin metal, aluminum, copper, brass, PVC, etc.