The HSS Twist Drill Bit TiN-coated offers maximum lifetime while drilling holes in metal. When using the appropriate cooling system, the drill bit has the lowest possible level of friction and minimal wear, due to its titanium-nitride coating. The high surface quality of this ground twist drill bit, which is made from HSS (high-speed steel), allows for extended usage. It is suitable for use on alloyed and non-alloyed steel, malleable cast iron, sintered iron, new silver, copper, bronze and hard plastics such as perspex.