This is a professional 13-PCS drill bit set. It includes drill bits with tip diameters of 1.5mm, 2mm, 2.5mm, 3mm, 3.2mm, 3.5mm, 4mm, 4.5mm, 4.8mm, 5mm, 5.5mm, 6mm, 6.5mm, each size comes with one piece. Industrial grade high-speed steel for higher durability and sturdiness. Suitable for drilling in tough material, including aluminium, cast iron, brass, copper, magnesium alloy, plastics, etc. for DIY, home and general building/engineering use. Feature - Color: Assorted Color - Material: Tungsten steel - Size: 11x0.5x0.5cm - diameter (mm) : 6.35 - Angle of outer (°) : 135 - Bit diameter: 1.5mm, 2mm, 2.5mm, 3mm, 3.2mm, 3.5mm, 4mm, 4.5mm, 4.8mm, 5mm, 5.5mm, 6mm, 6.5mm - High-speed steel with tungsten coating treatment, tougher and more abrasion resistant for longer working life and high work efficiency. - design drill bits, accurate and fine, increase drilling speed. - 13 sizes of tip: 1.5mm, 2mm, 2.5mm, 3mm, 3.2mm, 3.5mm, 4mm, 4.5mm, 4.8mm, 5mm, 5.5mm, 6mm, 6.5mm, 1 piece of each size, totally 13pcs. - Mainly for drilling wood, plastic, fiberglass, printed circuit board, and metal including copper, aluminum, tool steel, cast iron, and heavy-duty abrasive alloy metal, etc. - for home DIY, building and engineering use etc. Package list: 2 Sets x Precision Drill Bit