Item Type: Parallel Shank Twist Drill Material: High speed steel Application: Hand drill, bench drill processing equipment, etc. Uses: Drilling stainless steel, copper, iron, aluminum alloy and other steel materials Size:(Approx.) Drill Size mm/inFull Length mm/in Working Length mm 4.0 / 0.16 74 / 2.91 43 / 1.69 4.2 / 0.17 74 / 2.91 44 / 1.73 4.5 / 0.18 80 / 3.15 47 / 1.85 Package List 10 x Parallel Shank Twist Drill 1Suitable for processing equipment such as electric drills and bench drills, drilling stainless steel, copper plates, iron plates, aluminum alloys and other steel materials. 2The drill is precisely made of titaniumplated highspeed steel, with high hardness and good heat resistance. 3The cutting edge has high strength and fast gouge speed, which effectively improves work efficiency. 4The S-shaped spiral groove of the drill bit is beneficial to lead out the shavings and save time and effort. 5Using a powerful grinding wheel makes the blade groove sharper and smoother, making the drill more robust and durable.