is made from speed steel of hardness and good wear resistance. is coated with which give the a beautiful color and will not fade easily. This single can be used for drilling a wide of hole sizes from 3mm to 13mm. is most commonly used on softer materials such as thin iron sheet, aluminum, PVC and board of 5mm Step drill is great for use in work where thin steel, aluminum boxes and are encountered., Manufacturer: huswdw