Description:Feature:- HIGH-QUALITY MATERIALSIt is made of high quality YG8 alloy as raw material. The process of oxynitriding of the cutter head strengthen the drill hardness.ultimate drill bits, anti-crack tile drilling tool set.- SURFACE ELECTROPHORETIC PAINT PROCESSFull-grinding and anti-rust treatment, clean and sharp without burrs .The drill bit is more wear-resistant and more durable .Fully automated polishing: Polished CNC is fully automated, each one is unified.- UNIQUE CROSS ANGLE DESIGNSmall incision resistancefeature drilling stably, fast speed, not breaking the border. Opening neat, smooth, no broken edges, no tremor phenomenon, chip easily. ,Glass Drill Bit.- WIDE USAGEProfessional glass and tile drill bits provide smooth and accurate drilling in ceramic tiles, marble, thin iron plate, mirrors and glass. Remember to add Water or coolant when drilling. ,Concrete Drill Bit Set.- DIFFERENT SIZESSuitable for your different needs.It Can be installed in the general electric hand drill, bench drill.Specifications:Material: Cemented CarbideProduct Diameter: 3/4/5/6/7/8/10/12 mmWeight of Each: 3mm(11g), 4mm(12g), 5mm(14g), 6mm(15g), 8mm(18g), 10mm(24g), 12mm(39g)4Pcs/Set: 6mm+8mm+10mm+12mm5Pcs/Set: 3mm+4mm+5mm+6mm+7mm7Pcs/Set: 3mm+4mm+5mm+6mm+8mm+10mm+12mmPackage Included: 4/5/7Pcs Anti-Crack Tile Drilling Tool Set (At your option)