* HIGH-QUALITY MATERIALS --- It is made of high quality YG6X alloy as raw material. The process of oxynitriding of the cutter head strengthen the drill hardness. * SURFACE ELECTROPHORETIC PAINT PROCESS --- Full-grinding and anti-rust treatment, clean and sharp without burrs .The drill bit is more wear-resistant and more durable .Fully automated polishing: Polished CNC is fully automated, each one is unified. * UNIQUE CROSS ANGLE DESIGN --- Small incision resistance?feature drilling stably, fast speed, not breaking the border. Opening neat, smooth, no broken edges, no tremor phenomenon, chip easily. * WIDE USAGE --- Professional glass and tile drill bits provide smooth and accurate drilling in ceramic tiles, marble, thin iron plate, mirrors and glass. Remember to add Water or coolant when drilling. * 5 DIFFERENT SIZES --- Suitable for your different needs.It Can be installed in the general electric hand drill, bench drill. The machine drill clamp range is 10mm and above.