The Irwin Turbomax range of drill bits are suitable for portable and cordless drills. They are primarily designed for drilling metal and sheet metal but also performs exceedingly well in all types of wood and plastics and can be used for drilling stainless steel. Please note that if used for drilling stainless steel, a coolant should be always be used.Irwin Turbomax HSS Drill Bit (2). Size 5.0 x 86mm.