Features: 5pcs/set Efficient Universal Hole Drilling Tool, 3-7mm Triangular Drill Bit, Multifunctional Cross Alloy Drill Point High Performance Woodworking Utility Tools Application: cement wall, concrete, tile, wood, metal, stainless steel, aluminum alloy, wood, bubble brick, etc. Features: Materials Cemented carbide Color: Bronze Product size: 370/470/576/677/778mm Package Contents: 5 Pieces Universal Drilling Tool Various Sizes3mm, 4mm, 5mm, 6mm, 7mm, suitable for your different needs. It can be installed in the general electric h drill, bench drill. The drill clamping range is 10mm above. Unique Cross Angle DesignLow cutting resistance, stable drilling, fast speed, without breaking the boundary. Neat opening, smooth, no broken edges, no wobble phenomenon, easy to peel off. Fine workmanship Comprehensive rust-proof treatment. The drill is more wear-resistant more durable. Fully automated polishing: CNC polished is fully automated, each one is unified. High-quality materialsIt is made of high-quality alloy as the raw material. The oxynitriding process of the cutting head reinforces the hardness of the bit. Powerful drill bits. Wide UseProfessional glass tile drill bits provide smooth precise drilling in ceramic tiles, marble, thin iron plates, mirrors glass. Remember to add water or coolant when drilling.