1pc HSS Step Drill Bit 4mm-12mm Spiral Flute Triangular Shank Drilling Tool Features: The step drill bit is made from high speed steel of high hardness and good wear resistance. Surface is coated with titanium which give the drill bit a beautiful gold color and will not fade easily. This single drill bit can be used for drilling a wide range of hole sizes from 4mm to 12mm. It is most commonly used on softer materials such as thin iron sheet, aluminum, PVC and wood board of 4mm or thinner. Step drill is great for use in work where thin steel, aluminum or plastic boxes and chassis are encountered. Specifications: Material: High speed steel Surface Finishing: Titanium coating Step Size: 4mm, 6mm, 8mm, 10mm, 12mm Triangular Shank: 6mm Quantity: 1pc Package Includes: 1 x Step Drill Bit