This 4-22mm step cone drill bit is suitable for cutting hole in a variety of materials including steel, brass, wood, plastic, etc. Features: Manufactured from high speed steel for increased durability and cutting power. Titanium coated to reduce friction and heat. 2mm step increments. Compared with the ordinary twist drill, is not easy to be broken. Specially designed for precision drilling of holes in aluminium, brass, copper, plastic, steel and wood. Specifications: Material: High-speed steel Color: Gold Size: 4-22mm (6,8,10,12,14,16,18,22mm) Shank Size: 25 * 6mm / 0.98 * 0.24in Total Length: 75mm / 2.95in Package Weight: 50g / 1.76ounces Package Size: 80 * 30 * 30mm / 3.15 * 1.18 * 1.18in Packing List: 1 * Step Cone Drill Bit