Features: brand new and high quality ● High-quality material: It uses cemented carbide as for raw material. The oxynitride technology of the bit strengthens the hardness of the bit. ● Surface electrophoresis coating process: thorough, clean, for sharp grinding and anti-oxidation treatment, no burrs. The drill bit is more wear-resistant and durable. Fully automatic polishing-polishing CNC is fully automatic, and each piece is uniform. ● Unique for cross right-angle design: low cut resistance, stable drilling characteristics, high speed, and no tearing of the cutting edge. Clean, smooth opening, no broken edges, no shaking phenomenon, not easy to chip. ● Wide range of uses: professional glass and tile drill bits provide smooth and precise drilling on tiles, marble, thin iron plates, mirrors and glass. Remember to add water or coolant when drilling. ● 5 different sizes: suitable for your different needs. Can be installed on general hand drills and for bench drills. The clamping range of the machine drill is 10mm and above. Specifications: Material:Cemented Carbide Color ：Black Size1: Approx.3mm/0.11inch Size2: Approx.4mm/0.15inch Size3: Approx.5mm/0.19inch Size4: Approx.6mm/0.23inch Size5: Approx.7mm/0.27inch Package Includes: 5PcsxTriangle Bit note: 1.Please allow 1-2mm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.