description: 100% new high quality The surface is of painted and full grinding processing with anti-rust treatment which is smooth to drill. Single threaded U-type chip discharge groove make it smoother to drill. The design of triangular make it more fastening to clamp and not easy to slip. Color as shown Material: Hard Alloy Tool Holder Type: Triangle Cooling Type: Outer Cold Blade Top Corner: 45° Category: Hole expansion drill Optional Style: 4-10mm(5pcs)4mm 5 mm6mm 8mm 1 0mm 6-12mm(5pcs)6mm,6mm 8 mm10 mm12mm 3-12mm(7pcs)3mm 4mm 5mm 6 mm8mm 10 mm12mm Diameter: 2.5-9mm Chip Groove Length: 40-75mm Blade Diameter: 3-12mm Blade Length: 80-120mm Uses: Widely used in ceramic tile, glass, brick wall, wood, etc. Can be used in the hand electric drill, table drill, etc. Packing: 5Pcs 4-10mm Drills 5Pcs 6-12mm Drills 7Pcs 3-12mm Drills(based on your choice)