Features 1、The drill shank cuts the three‑dimensional triangular, so that the electric drill clamping is more tight and the drilling does not slip. 2、High quality high speed steel material, strong toughness, wear resistance. 3、U‑shaped spiral grooves, conducive to drilling more smoothly, convenient to use. 4、Widely used in glass, ceramic tile, plastic, wood and other materials drilling. 5、Including 5pcs drill bit of the package, meeting your different needs. Specification Condition: 100% Brand New Item Type: Center Drill Material: High Speed Steel Color: Blue Usage: Widely used in glass, ceramic tile, plastic, wood and other materials drilling Type Total Length Working Length Blade Diameter Handle Diameter Total Weight 4mm 83mm / 3.3in 45mm / 1.8in 4mm / 0.16in 3mm / 0.2in 5.5g / 0.2oz 5mm 81mm / 3.2in 49mm / 1.9in 5mm / 0.2in 3mm / 0.3in 6.6 g / 0.23 oz 6mm 101mm / 4in 55mm / 2.2in 6mm / 0.24in 5mm / 0.2in 12.5g / 0.4oz 8mm 118mm / 4.6in 71mm / 2.8in 8mm / 0.3in 8mm / 0.3in 29.8g / 1.1oz 10mm 120mm / 4.7in 70mm / 2.8in 10mm / 0.4in 7mm / 0.28in 36.6g / 1.3oz Package List 1 x 4mm Drill Bit 1 x 5mm Drill Bit 1 x 6mm Drill Bit 1 x 8mm Drill Bit 1 x 10mm Drill Bit