How to sharpen a drill on metal with your own hands: video, adaptation, because of
Qualitatively perform metal processing (including drilling a hole in a metal part) impossible without the use of a tool, mechanical characteristics and geometric parameters of which correspond to the required values. That is why the question is, how to sharpen a drill on metal correctly, relevant for home builders, who often work with such a tool, wearing out (which is natural) during operation.
Sharpening a drill on metal with a special device significantly simplifies the task
Sharpen drills, are intended for works on metal, accounted for much more often, than those, by means of which wood processing is carried out. When processing such a soft material, which is wood, drills are practically not blunted and can be successfully operated for a very long time, fully retaining its original characteristics. The situation with drills is completely different, by means of which openings in details from metal are made. The condition of such drills should be monitored constantly and measures should be taken immediately, if their working part has undergone wear.
About that, that the drill on the metal must be sharpened, shows a number of signs:
- creaking and humming, issued as a worn tool;
- intensive heating of the drill in the process of its use;
- low quality of the created openings.
In drills with different lengths of cutting edges only one side works and the chips come out on one spiral groove
Working with a worn drill is not only inefficient, but also dangerous. At any time such a drill, on the working part of which there are significant loads, that can break, and its individual fragments, fly in different directions with great speed, can cause serious injury.
Drill sharpening parameters
As in production, and at home drills on metal can be sharpened on emery machines, equipped with a grinding wheel of appropriate hardness. It is best to use standard equipment in such cases. If it is not available, then you can sharpen drills on devices, made with their own hands. It should be borne in mind, what are the characteristics of this equipment, as well as devices for sharpening drills, used with it, largely determine the quality of such a procedure.
The main forms of sharpening of spiral drills
The most important parameters, which should be taken into account, to properly sharpen the drill on the metal with your hands, is:
- angle, under which the rear of the tool is located on the plane of drilling;
- sharpening angle of the front surface of the cutting part;
- the length of the transverse jumper on the cutting part;
- angle at the top of the cutting tool;
- length of cutting edges.
The main parameters of sharpening a drill
That sharpening of a drill was qualitative, it is necessary to ensure its supply to the processing area at the desired angle. Various devices are used to solve this problem, which are equipped with grinding machines.
It should be borne in mind: if sharpening of a drill on metal will be executed incorrectly, this can lead not only to poor quality results, but also to tool breakage.
Influence of the angle at the top on the correct formation of chips
What is needed for the procedure
To sharpen the drill on the metal itself, must first be determined, to solve which tasks it will be used. In production conditions for sharpening of drills, usually, special devices are used, ensuring maximum accuracy and productivity of such process. When sharpening drills at home, you always have to look for ways, that make the result of this process high quality.
The minimum set for sharpening drills for metal should be included:
- sandpaper;
- grinding wheels of different hardness, which are determined depending on the material of the drill, which must be sharpened;
- coolant tank and the liquid itself, as which ordinary water can be used (or machine oil);
- adaptation, that can withstand the correct sharpening angles.
The rack for sharpening of drills is established near an abrasive disk and allows to sharpen a cutting edge at an exact angle
When sharpening drills with your own hands you need to pay attention to the following parameters:
- the angle between the plane of the front of the drill and the base of its cutting edge (such an angle, measured in the main cutting plane, called the front);
- rear corner, which is measured in the same way, as well as front, but on the back plane of the drill;
- angle at the top of the tool, measured between two cutting edges.
For sharpening of drills on metal according to all rules it is necessary to adhere to the following values of the above-stated parameters:
- the front angle of the cutting part is 20 °;
- rear angle - 10 °;
- the angle at the top is 118 °.
Table 1. Angles at the top of the drill depending on the material being processed
Table 2. Rear and front corners of the drill
If you need to sharpen a drill bit on metal at work or at home, you must strictly adhere to safety precautions. This process is accompanied by the formation of a large number of sparks, from the influence of which it is necessary to protect the organs of vision. in addition, as this procedure is performed with sharpened metal tools, it should be carried out, using gloves to protect hands.
Practical recommendations
Sanding machine, equipped with a grinding wheel, is a universal device, that allows to sharpen a drill on metal qualitatively even in house conditions. Using such a device, the technological operation should begin with the processing of the rear surface of the tool. Drill, which must be sharpened, hold in relation to the grinding wheel as follows, so that its cutting part is parallel to the surface of the circle. Sharpening, performed according to this method, is optimally suitable for drills on metal, whose diameter does not exceed 10 mm.
To sharpen drills, whose diameter is larger 16 mm (including equipped with carbide plates), it is best to use an emery board with a special device. The use of the latter allows not only to control the sharpening angle of drills of large diameter, but also to perform such a process with maximum safety.
Accuracy of sharpening in the special device is reached by exact adjustment and reliable fixing of a drill in a mandrel.
Grinding machines, equipped with additional devices, recommended for use in those cases, when it is necessary to sharpen drills of the following categories:
- used for drilling blind holes, which is characterized by a decrease in axial cutting force;
- universal, characterized by increased strength;
- are used for drilling deep holes and have a small amount of sharpening.
Main task, which is solved by the device, allowing to sharpen qualitatively a drill on metal on the grinding machine, - this is the correct orientation of the cutting part of the tool relative to the surface of the abrasive wheel. That is why the design of such a device has a special base plate. The machine itself is installed on it, engine, which rotates the grinding wheel, as well as a turntable, on which the processed tool is fixed. Use of such column allows to sharpen drills practically in any spatial position, placing their cutting part in relation to the surface of the grinding wheel at the required angles.
Advantages of using special devices
The great advantage of using grinders, equipped with special devices, there is that, that the movement of the processed tool on them is provided by the drive, connected to an electric motor. The structural scheme of such a drive includes a bearing assembly and a shaft. At the end of the latter and the drill is fixed, which must be sharpened.
Before the procedure, the tool is fixed on the device at the required sharpening angles. After the drill on the metal is fixed on the movable column of the device, it itself is brought to the rotating grinding wheel. So, all angles, which must be formed on the rear surface of the cutting part, maintained in the process of sharpening automatically. Among the main disadvantages of such a machine for sharpening drills is usually noted its large size.
The machine for sharpening of drills
If you are looking for an answer to that question, how to properly sharpen a drill on metal, without performing complex manipulations with the tool, you can recommend more compact devices. One such device is a machine attachment. It is mounted on the spindle of a conventional electric drill, from which its main working element - a grinding wheel is put in rotation. One end of this device is equipped with a special coupling, connecting the device to the rotating spindle of an electric drill, and the other with a lid with holes of different diameters, in which working parts of sharpened drills on metal are inserted.
Nozzle on a drill for sharpening of Sparta drills
Teach someone to use this device, which allows you to quickly sharpen the drill at home, very easy. You can not even show this process on video or live, everything is clear and without demonstration. To sharpen a drill bit on metal with such a device, it is enough to insert the tool into the hole of the appropriate diameter to the stop and turn on the electric drill, which will rotate the grinding wheel. The tool sharpened by means of such simple device possesses all necessary geometrical parameters.
It would seem, you can sharpen the drill with any device, able to rotate the grinding wheel. Meanwhile, without the use of devices for fixing the tool during sharpening, you can perform this procedure qualitatively. in addition, you can get serious injuries. It is possible to address to such simple way of sharpening only in that case, if you need to sharpen small diameter drills, which are difficult to hold in your hands during processing.
At manual turning to maintain the necessary parameters the corner fixed on a support will help
After you have trapped the drill on the metal, it is necessary to perform such a technological operation, as proof. She is needed for that, to bring the quality of the cutting part of the restored tool to the required values. Finishing is performed using grinding wheels with low grain size. At the same time from the cutting part of a drill all roughnesses are eliminated, it is given smoothness. Drills, on the working part of which there are no roughness, create less friction during drilling, less heated, so, able to last longer. To perform finishing operations as in production, and grinding wheels are used at home, made of silicon carbide.
An important condition for quality sharpening is the absence of vibration of the abrasive stone
Drills, the working part of which is equipped with solders from hard alloys, can also be sharpened, but a number of nuances should be taken into account. Carbide inserts are very critical of overheating, therefore it is possible to sharpen qualitatively such drills on metal only at low speeds of rotation of a grinding wheel. in addition, performing sharpening, it is necessary to monitor that, so that the tool does not overheat. Otherwise, the carbide plates crack or even break off at the solder joint.
To sharpen carbide inserts, it is possible to follow technologies of processing of usual cutting tools. It should also be borne in mind, that for sharpening of drills with hard-alloy plates use grinding wheels with a diamond dusting, as only they can effectively cope with the processing of such solid material.
For, to get acquainted in detail with the rules and methods of sharpening drills on metal, it is better not to be limited to theoretical material, and study the relevant videos. The technological process shown in all details will allow you to sharpen the tool qualitatively and quickly.
