Materials: The drill bit set is alloy as raw material. The oxynitride process of the cutter head enhances the hardness of the bit. Surface electrophoretic painting process: The drill set is comprehensive and rust-proof grinding processing, clean and sharp without burrs. The drill is more wear-resistant and more durable. Fully automated polishing, polishing is fully automated, each one is unique. Unique cross angle design: Small incision resistance, stable drilling functionality, fast speed, without breaking the boundary. Neat opening, smooth, no broken edges, no wobble phenomenon, easy to peel off. 5 different sizes: Suitable for your different needs. It can be installed in the general electric hand drill, bench drill. The clamping range of the machine drill is 10mm and above. Widely used: Professional glass and tile drill bits provide smooth and precise drilling in ceramic tiles, marble, thin iron plates, mirrors and glass. Remember to add water or coolant when drilling. Specifications: Materials: Cemented Carbide Product weight: 125G Product size: 3*704*705*766*777*80MM Package Included: Universal Drilling Tool (5pcs)*1