Features: Twist drill bits are made of high-speed steel, anti-corrosion and durable to use. 4 different specifications of twist drill bits for your choice, meet your different needs. Long cutting edge allows you using these bits to drill deep holes. Incisive twisted drill bits will make the drilling easier and more effortless. Suitable for most drilling jobs and materials such as thin metal, aluminum, iron, carbon steel, wood, plastics, etc. Specification: Material: High Speed Steel Weight: 163-244g/5.7-8.6oz Shank Diameter: 1/2'' Outside edge apex Angle: 130 Size: 16.5mm, 18.5mm, 19.5mm, 23.5mm (Optional) Package List: 2 x Twist Drill Package List 1Twist drill bits are made of high-speed steel, anti-corrosion and durable to use. 24 different specifications of twist drill bits for your choice, meet your different needs. 3Long cutting edge allows you using these bits to drill deep holes. 4Incisive twisted drill bits will make the drilling easier and more effortless. 5Suitable for most drilling jobs and materials such as thin metal, aluminum, iron, carbon steel, wood, plastics, etc.