Uxcell 12Pcs 5.5Mm Nitride Titanium Coated High Speed Steel Hss 4341 Twist Drill Bits

Specifications: Cutting Edge Diameter: 5.5mm / 0.217" Round Shank Diameter: 5.5mm / 0.217" Cutting Edge Length: 56mm / 2.2" Overall Length: 93mm / 3.66" Split Point: 135 Degree Material: 4341 High Speed Steel (HSS) Finish: Nitride & Titanium Coated (TiN Coated) Package: 12pcs x Twist Drill Bits Descriptions: 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. Good for applications requiring precise and efficient processing. Premium black nitride and gold titanium dual coatings can apply lubricant better for smoother drilling and are more durable and corrosion resistant. The black and gold finish helps to extend the tool life. The drill bits can drill clean and accurate holes in stainless steel, cast iron, A3 steel, carbon steel, aluminum alloy, copper, wood and plastic. Cutting edges provide neat and smooth cuts. Large spiral grooves facilitate the export of metal chips. Suitable for 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. Notices: NOT suitable for tiles, concrete, walls, stones. Controlling the speed is very important. The larger the diameter, the slower the speed required. Start the drill at a slow speed and gradually increase to the desired drilling speed. Make sure the drill bit is tightened securely, keep the drill bit perpendicular to the work surface, and apply steady pressure to the drill bit. 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.