Features: *100% brand new and high quality. *It is made of high quality YG6X alloy as raw material. The process of oxynitriding of the cutter head strengthen the drill hardness. *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. *Small incision resistancefeature drilling stably, fast speed, not breaking the border. Opening neat, smooth, no broken edges, no tremor phenomenon, chip easily. *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. Specifications: *Material: Cemented Carbide *Color: As picture show *Size: 3*70mm, 4*70mm, 5*76mm, 6*77mm, 8*80mm (Approx.) *Quantity: 5pcs Package Contents: 5*Universal Drilling Tool Notes: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data.