How To Master The Grinding Scale Of Straight Handle Fried Dough Twists Drills?

The straight shank Fried Dough Twists drill is a commonly used drilling tool. It has a simple structure and is easy to grind. Grinding the drill bit well is important for machining workpieces, but it is not an easy task to truly grind it well. The key is to master the methods and techniques of grinding. Once the methods are mastered, coupled with multiple grinding experiences, one can effectively grasp the grinding scale of the drill bit.
How to master the grinding scale of straight handle Fried Dough Twists drills?
1. Before grinding the drill bit, the main cutting edge of the drill bit should be placed on a horizontal plane with the grinding wheel surface, which means that when the cutting edge contacts the grinding wheel surface, the entire edge should be ground. This is the first step in the relative position between the drill bit and the grinding wheel. Once the position is set, slowly move it towards the grinding wheel surface.
2. This angle is the tip angle of the drill bit. If the angle is not correct at this time, it will directly affect the size of the drill bit tip angle, the shape of the main cutting edge, and the cross cutting angle. This refers to the positional relationship between the axis of the drill bit and the surface of the grinding wheel, taking 60 ° is sufficient, which is generally more accurate to see. Here, it is important to pay attention to the relative horizontal and angular positions of the drill bit before grinding. Both should be balanced and taken into account. Do not neglect the proper angle or angle in order to level the cutting edge.
3. After the cutting edge contacts the grinding wheel, it should be ground backwards from the main cutting edge, that is, starting from the cutting edge of the drill bit to contact the grinding wheel first, and then slowly grinding downwards along the entire back cutting surface. When the drill bit is cut in, it can gently touch the grinding wheel, first perform a small amount of grinding, and pay attention to the uniformity of the sparks. Adjust the pressure on the hand in a timely manner, and also pay attention to the cooling of the drill bit. Do not let it burn too hard, causing the cutting edge to discolor and eventually anneal. When the temperature of the cutting edge is found to be high, the drill bit should be cooled in a timely manner.
4. This is a standard drill bit grinding action, where the main cutting edge swings up and down on the grinding wheel, meaning that the hand holding the front of the drill bit should evenly swing the drill bit up and down on the grinding wheel surface. But the hand holding the handle cannot swing, and it is necessary to prevent the back handle from tilting upwards, that is, the tail of the drill bit cannot be raised above the horizontal centerline of the grinding wheel, otherwise it will make the cutting edge dull and unable to cut. This is the most crucial step, whether the drill bit is well ground or not is closely related to it. When the grinding is almost done, start from the edge of the blade and gently rub against the back corner to make the back of the blade smoother.