The drill bit of twist drill is processed by milling machine. Twist drill is a tool to process holes from solid materials, and it is also the most widely used tool in hole processing. Twist drill is a tool to drill a round hole of a workpiece through its rotary cutting relative to a fixed shaft. It is named because its chip groove is spiral and looks like a twist. Spiral grooves have 2 grooves, 3 grooves or more, but 2 grooves are the most common. Twist drills can be clamped on manual and electric hand-held twist drills or drilling machines, milling machines, lathes and even machining centers. The drill bit material is generally high-speed tool steel or cemented carbide.
Zhijia tool