Taper Length Drills have a longer flute and overall length than jobbers drills and are used in hand held drills and machines for drilling deep holes in a variety of normal steels, cast iron, ferrous and non-ferrous metals and alloys. High Speed Steel taper length drills have a standard two flute, 118 degree point design for general purpose applications. Heavy duty models feature a TiN-coating, parabolic flute design, a higher helix angle and a 135 degree split point which reduces bit walking and feed rate. Heavy duty high speed steel taper length drills are suitable for alloy steels, managanese steels and other difficult materials, while cobalt steel long drills are the optimum choice for harder stainless steels. For the best performance and tool life, use suitable cutting oils or coolants as recommended.