【Materials】These twist drill bits are made of high-speed steel for high hardness and durability. The use of high-speed steel drill bits improves machining efficiency and convenience. 【Size】This set contains 8 drill bits in various sizes, including the most popular ones: 4mm, 4.2mm, 4.5mm, 5mm, 5.2mm, 6mm, 8mm, and 10mm. 【Design】The extra-long cutting edge allows you to drill deep holes. The sharp head design provides a center point, high maneuverability, and faster drilling with less effort. 【Applications】They are ideal for drilling most materials and soft materials. Suitable for most drilling jobs and materials such as thin metal, aluminum, iron, carbon steel, wood, plastics, etc. 【Advantage】Sharp twist drill bits make drilling easier and effortless. Incisive twist drill bits will make drilling easier and more efficient. The long cutting edge allows you to use these drill bits to drill deep holes. Product Features: The twist drill bits are made of high-speed steel for high hardness