The home master always has a tool in hand and at hand: a drill or a perforator. But the drill quickly erased, blunted. As a result, you have to throw them away and look for new ones in stores. But the real owner will save his time and try to figure out on his own how to properly grind a drill bit for metal and what tools will be required for this.
What are the drills
They vary in metal and diameter. Their characteristics depend on their intended use for processing specific types of material: for wood, stone, metal. The latter type is easiest to sharpen at home. Let us dwell on it. Each drill has 2 rear surfaces that give the tip of the tool a conical shape, and 2 cutting edges. If it is placed on a horizontally located washer, then the cutting edges will touch it, and the part behind them will lag behind them. It is located at a certain angle, which is called the "rear". The runoff should approximately be 0.2 mm for each twist. All this you need to know if you are going to sharpen a drill for metal with your own hands, for example, having organized a workplace in the garage. Indeed, when processing the tool you need to give the correct shape.
How to organize a workplace
You will need a grinding wheel. But you can do without it. For example, to adapt a power tool: a grinder with a rotating disk or an electric drill. The main thing is to install it on a workbench and fix it well. When sharpening, the quality of the metal changes (it loses its ductility), and the drill heats up. To avoid this, you need to install a jar of water nearby. It will have to periodically immerse the processed tool. You can use machine oil instead of water. Before sharpening drill bits for metal, care must be taken to avoid personal injury. Eyes must be protected with special glasses, they will protect against chips and crumbs.
Sharpening
Starting to process the tool, you must remember that it must be at the same angle. Press the drill bit against the grinding wheel tightly. The process of sharpening on an electric ejector consists of several stages. First, the tip of the drill is formed, then the cutting edge, and finally the grinding of the back surface is performed. Ideally, after processing, the back should be in the shape of a cone, and the cutting edge should have an ideal angle.
When the bulk of the work is done, it’s the turn of refinement. A master professional will be able to tell how to sharpen a drill for metal correctly. He can be called in mentors. If you want to master this business on your own, then start experimenting with broken, dull tools. As a result of processing, a jumper is formed. For drills with a diameter of up to seven millimeters, its length should be from 0.5 to 0.7 millimeters. For larger ones, it can be from one to one and a half millimeters. If the drill has a large diameter, then it is necessary to remove the edges on the shank. They experience great resistance to cutting. To do this, you need to very accurately mark the circumference of the tool in three parts. Now you need to very carefully remove the metal to an equal depth on them.
Jumper processing
Another important point: you need to know how to sharpen a drill bit for metal and process a jumper. Most often, at home on a grinding machine it is difficult to achieve the desired result. The ribbon is needed in order to reduce the load on the drill, increase the speed and accuracy of drilling. The whole process is as follows. The jumper and the back edge are made at the edge of the circle at a slow speed. The drill should touch the sharpener for a short time. Then it must be taken aside, turned one hundred and eighty degrees, again pressed to the circle. Periodically, if the metal is heated, the workpiece must be dipped in water so that it does not lose elasticity. If you use a wet abrasive bar, then the risk of spoiling the drill is significantly reduced.
Sharpening check
After completion of the process, it is necessary to check the quality of the work done, the symmetry of sharpening. In order to make sure how the correct sharpening of the drill bit for metal was carried out, you can arm yourself with a magnifying glass or use a drill. Insert the machined tool into it and bring the felt-tip pen to the cutting edge. Then turn off the drill and check where there is a mark on the drill. If one side is dirty more than the other, then it needs to be sharpened. The second method is to drill plastic with a hand drill. On the side where more shavings go, the edge of the drill is larger. It needs to be finalized. After you succeed in sharpening the drill bit for metal, you will receive a tool with restored working qualities. To save them for a longer period, you need a box. In order to avoid their damage, blows against each other or other objects, they should be wrapped in oiled cloth or tied with an elastic band.