Feature - Premium Material: adopts imported tungsten carbide, high strength, high hardness and endurance, great abrasion resistance, resistance to bending for longer working life and high work efficiency. - Extraordinary sharpness: Adoption of nanotechnology and advanced grinding technology, the cutting becomes sharper than before, which can reduce the cutting force and drill breaking, improve the drilling accuracy. - Strictly symmetrical cutting edge: Conducive to efficient cutting and avoids drilling deviation. - 10 Assorted sizes: The drill bit set comes in different sizes for each for meeting your using requirements. - Wide application: For drilling PCB, SMT, CNC, mold, plastic, copper, stainless steel, fiberglass, wood, metals, engraving, jewelry making and other precision parts processing. Specifications - Color: Random - Material: Tungsten steel - diameter: 3.175mm - Full length 38.1mm - Bit diameter: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm