Material: 4241 high speed steel (HSS), coated with titanium. This tricone drill bit set is well designed and allows you to achieve the desired drilling diameter without changing drill bits multiple times. According to the machining requirements of holes of different diameters, single macro machining can be completed without changing drill bits and hole positioning. This drill bit is a new type of high speed steel large pitch cone drill with titanium countersink drill bit set, made of high quality high speed steel and coated with titanium coating to reduce friction and heat. Ideal for a variety of materials, openings and holes including metal, aluminum, wood, plastic and more. Can be used on thin metals, aluminum, copper, brass, PVC, etc.