Twist drill is a tool for drilling the round hole of a work-piece by means of its rotary cutting with a fixed axis. Spiral grooves have 2 grooves, 3 grooves or more, but 2 grooves are the most common. Twist drill bit can be used in manual and electric hand held drilling tools or drilling machines, milling machines, lathes and even machining centers. The drill bit material is generally high-speed tool steel or cemented carbide.
Methods and Skills of Twist Drill
“Less grinding” first means “no grinding”. If you get the drill bit and grind it in a hurry, it must be blind grinding. Only by placing the position before grinding can we lay a solid foundation for “grinding” in the next step, which is very important. In the process of demonstration, teachers can explain and demonstrate in the form of easy to understand formulas according to the methods and skills summarized in practice. Students often understand, see and master them easily. When demonstrating, the action should be correct, and the demonstration of normal action, step-by-step action and slow action should be done well, so that students can accept it easily. Here, four phrases are used to guide the grinding process. The effect is good.
Pithy formula 1: “the cutting edge flattens the wheel surface.” This is the first step in the relative position between the drill bit and the grinding wheel. Some students often lean against the grinding wheel to start grinding before leveling the cutting edge. It must not be polished well. The “edge” here refers to the main cutting edge, and “leveling” refers to that the main cutting edge of the sharpened part is in a horizontal position. “Wheel surface” refers to the surface of the grinding wheel. “Lean” means to move closer slowly. At this time, the drill bit cannot contact the grinding wheel.
(Please refer to passage Analysis of Twist Drill’s Knowledge and Methods Ⅱ to read the following content.)
Post time: Feb-20-2022