Item Type: Twist Drill Bit Material: High speed steel Application: Hand drill, bench drill processing equipment, etc. Uses: Drilling stainless steel, drilling copper, drilling iron, drilling aluminum alloy and other steel materials Drill size(mm)(approx.)Overall length(mm)(approx.)Working length(mm)(approx.) 7mm / 0.3in108mm / 4.3in69mm / 2.7in 7.5mm / 0.3in109mm / 4.3in70mm / 2.8in 8mm / 0.3in116mm / 4.6in75mm / 3in 8.5mm / 0.3in116mm / 4.6in75mm / 3in 9mm / 0.4in125mm / 4.9in81mm / 3.2in 9.5mm / 0.4in125mm / 4.9in81mm / 3.2in Package List 10 x Drill Bit 1Suitable for processing equipment such as hand drills and bench drills, and can drill stainless steel, drill copper, drill iron, drill aluminum and other steel materials 2The drill bit is precisely made of tiplated highspeed steel, with high hardness, good heat resistance and long service life 3High cutting edge strength, fast gouge speed, fine workmanship can effectively improve work efficiency 4The drill bit has an Sshaped spiral groove, which is beneficial to send out the shavings and save time and effort during operation 5Using a powerful grinding wheel to make the blade groove sharper and smoother, making the drill more robust and durable