10Pcs 5.5Mm Nitride Titanium Coated High Speed Steel (Hss) 4341 Twist Drill Bits

4341 high-speed steel contains high content of carbon and alloy elements, providing excellent cutting performance, high heat resistance, high hardness, wear resistance and durability. Suitable for applications requiring precise and efficient processing. Black nitride and gold titanium dual coatings can apply lubricant better for smoother drilling and are more durable and corrosion resistant. Large spiral grooves facilitate the export of metal chips, saving time an effort. The 135 degree fast cutting point penetrates quickly with less pressure and prevents walking on metal surfaces. Drill bits can drill clean and accurate holes in stainless steel, cast iron, carbon steel, aluminum alloy, copper and brass. Cutting edges provide neat and smooth cuts. NOT suitable for tiles, concrete, walls, stones. The twist drill bit can be used with handheld drills, drilling machines, bench drills, machining centers, CNC lathes. Use an appropriate lubricant (such as cutting fluid or oil) to reduce friction and heat build-up. Make sure the drill bit is tightened securely, and keep the drill bit perpendicular to the work surface. Note: The larger the diameter, the slower the speed required. Start the drill at a slow speed and gradually increase to the desired drilling speed. If the hole is larger than 6mm, first drill a small hole with a 3.2mm-4mm drill bit, and then use a larger drill bit to enlarge the hole.