The R56CO drill bits in the C8R56CO set are manufactured from premium High Speed cobalt and can be used to drill a number of materials including stainless steel, aluminum and steels. Add to this the suitability for many different machine and hand held applications and you have a very versatile drill. The set includes eight fractional sizes from 9/16? to 1 inch in 1/16 ? increments in a sturdy case to keep the drills safe and in size order so it?s easy to select the size you need. The self-centering split point reduces the thrust needed and makes sure the drill does not slide over the surface of the workpiece, whilst the steam oxide finish prevents workpiece material from sticking to the cutting edges of the tool for clean, accurate holes. All of the drills have a 1/2" parallel shank to enable large diameter drills to be held in conventional hand-held power chucks without slipping. As a final, great feature, the tools are manufactured from High Speed cobalt for great drilling in many materials including steel, aluminum and stainless steel.