The C60R18CO set of drills, consisting of 60 different R18CO drill bits in letter sizes from N1 to N60. The drills are of a heavy duty design, recommended to use in difficult materials and applications and are manufactured from High Speed cobalt, for drilling hard materials including tool steel. To help with self-centering and reduce the push force required, the drills have a 135 degree split point, whilst clean and accurate holes are ensured thanks to the steam oxide finish which prevents workpiece material from sticking to the cutting surfaces of the tool.