Twist drill is a tool used to drill round holes of workpiece by rotating cutting of its relative fixed axis. Because of its capacity chip groove into spiral shape and shape like hemp and named. Spiral grooves have 2, 3 or more grooves, but 2 grooves are the most common. Twist drill can be clamped on manual, electric hand-held drilling tools or drilling machines, milling machines, lathes and machining centers. Drill material is usually high - speed tool steel or carbide.