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, bubble brick, etc. Material: Cemented carbide Color: Bronze Product size: 3x70mm, 4x70mm, 5x76mm, 6x77mm, 7x78mm Package Contents: 5 Pieces Universal Drilling Tool Various sizes: 3mm, 4mm, 5mm, 6mm, 7mm, suitable for different needs. Can be used with standard electric hand drills and bench drills. Drill chuck compatibility: 10mm and above. Unique cross angle design provides low cutting resistance, stable drilling, high speed, and clean hole openings without chipping or wobbling. Smooth finish and easy material removal. Precision craftsmanship with rust-resistant treatment. Enhanced wear resistance and durability. Fully automated CNC polishing ensures consistent quality. Made from high-quality alloy material. Oxynitriding process increases cutting head hardness for superior performance. Suitable for professional use on glass, tiles, ceramic, marble, thin metal sheets, mirrors, and similar materials. Always use water or coolant during drilling to prevent overheating.