All about sharpening drills

People professionally engaged in construction are constantly dealing with different types of drills that are blinking over time. Poor-quality cutting elements come in disrete after a few months. Dear proprietary samples serve as its owners not one dozen years. And it is their builders who do not want to lose, but send for sharpening. In principle, this is the right decision, however, for the restoration of the state of the faded drill, you have to pay considerable money. And in order not to devastate your wallet, you can use the recommendations on sharpening with your own hands.

Basic Rules

Those who use drills once a year do not pay attention that it loses sharpness. But with this approach, one day it will simply won’t make a hole. And here you have to make an independent decision – either acquire a new drill, or restore the reinforced.

The process of sharpening on professional equipment does not require human efforts, which cannot be said about the restoration of sharpness with their own hands. However, before proceeding with a detailed acquaintance with the rules of sharpening and the intricacies of the process, it is necessary to know the signs that the drill will soon come into disrepair:

  • The cutting element is strongly heated;
  • From under the edge flies fine metal chips;
  • Noise from the working drill becomes many times stronger.

Special attention should be paid to the last feature. The friction force between the blocked edge of the spiral drills and the drilled plane increases, due to which the unusual noise occurs. With such a situation, it is necessary to immediately stop the work, otherwise the cutting element will be angry, its structure will change, so it will not be able to restore the drill.

Next, it is proposed to get acquainted with some rules and instructions of experienced masters involved in regular sharpening centering tips.

And that is noteworthy, from the proposed information it becomes clear that you can restore the drill with your own hands.

Process sharpening drill requires special equipment. In this case, we are talking about grinding machines and nozzles to drills and perforators. The grinding machine is a device equipped with a grinding stone. Nozzles to drills and perforators have an unusual shape of the tips. Often in private homes there is a miniature grinding machine, since it can be poured not only drills on this device.

Sharpening technology depends on the type of drill. Today on sale there are conical, screw, cylindrical, single-layer and two percentage cutting elements. Each of the presented types of cutting elements requires a special approach to sharpening, however, the total between them – only the rear edges are rearranged.

Manually do it is very difficult, but maybe. Especially when it comes to small specimens. Small and thin drills always appear manually, thanks to which a person feeds his hand in sharpening skills and after some time can put in order the cutting elements of large sizes.

Single-bed-type drills differ from their fellows presence of only one plane. The angle of incompetence according to the standard fluctuates in the range of 28-30 degrees. It is this part that can be restored. This beveled plane is deposited to inactive grinding stone. If the stone is rotated, the likelihood will be great that the drill will acquire the wrong angle. For a similar scheme, two percentage drills are reached. The only difference in sharpening process is the need to process two planes.

When restoration of conical drills, it is important to exercise special accuracy. It is impossible to break the conical edge shape. That is why the drill is required to bring to a rotating grinding stone, pressing the cutting element and oscillatory movements to attach the sharp cone. The main thing is not to pull the drill from the stone and conduct the entire procedure with one touch.

Important rule in the process of sharpening drills – maintain the edge shape. It is no secret that it is not possible in each case. Especially when it comes to sharpening drills with a diameter of 10 mm and less. However, for this type of cutting item, it is preferable to withstand only the rear angle.

As for the drill with a diameter of more than 10 mm, wool care professionals are advised to sharpen not only the edges of the planes, taking into account the angle excerpt, but also the front plane, which significantly improves the technical characteristics of the structure. Such a sharpening will be more efficient in drilling work.

Thanks to the correct assessment of the front plane, the angle of the cutting part of the drill becomes greater, which significantly increases the endurance of the metal element. Besides, It becomes less transverse length of the edge, which is why the product does not cut hole, but scraping.

After the sharpening procedure, it is necessary to enroll. Speaking with simple words, remove notes that occurred from the mechanical effects of grinding stone. With factory sharpening, this procedure is extremely important. Thus, it is possible to increase the level of wear resistance of the cutting element. At home, the finishes do not always manage to do, but if there are necessary devices, you cannot miss this procedure.

For home finishing, it is necessary to use a silicon or elb carbide stone. They can be purchased at any construction market. Silicon carbide stone is distinguished by green. Ideally, you should use a copy of the grade 63c with an indicator of grain grain 6 and hardness M3-SM1. If the choice fell on the stone from ELB, it is necessary to take an instance with an indicator of graininess in the range of 6-8. It is important to draw attention to the fact that the presented stones for the finishes must be made on the Bakelitis Big.

Separate attention should be paid to step drills. They can be purchased in the market as separate elements or as a set. The diameter of the stepped drills produced ranges in the range of 4-21 mm. Step drills are distinguished by high quality and wear resistance, but even such samples of the cutting elements are blocked. And, unfortunately, to restore the tip of the tip of the drill can only be in some models.

If we are talking about a winning drill, you should use a diamond circle for sharpening.


In the modern market, you can meet spiral drills, flat and centered models:

  • Spiral elements, according to their name, differ in a spiral form of edges;
  • Flat products are designed to trigge deep holes of large diameters;
  • Center drills are used for centening elements.

All presented varieties of drills are blinking over time. Reducing the sharpness of the cutting element prevents construction work. This means that the product must be renovated.

To date, 5 types of sharpening drills have been developed. Each individual method corresponds to the type of material of the cutting element and the specifics of its work.

  • “H” – this type of sharpening is universal. However, used when restoration of drills with a maximum diameter of 12 mm.
  • “NP” – in this case, the sharpening of short crossing.
  • “NLL” – the type of sharpening implies the elongation of the transverse edge and the ribbon width.
  • “DP” – in the professional sphere This type of sharpening is called “double”. In addition to the transverse edge, another 4-edges in the form of broken lines occur.
  • “DPL” – a description of the same way as the 4th method of sharpening, only tinting tape is added.

Sharpening angle

Previously mentioned before starting a drill sharpening, it is necessary to calculate the correct angle for the restoration of the cutting element. For the convenience of finding the correct indicator, a special table has been developed, where in the 1st column is the degree of inclination with a digital value, and in the 2nd – material designed for drilling.

Processed material

Sharpening angle

Steel, cast iron, bronze








Ceramics, Granit










Incorrectly exposed angle for sharpening leads to the fact that drill and power tools are heated during operation. And the quality of the drilled hole is reduced at times.

Requirements for instruments

In industrial conditions, the sharpening is carried out on specialized equipment subject to safety regulations. However, several other devices have been invented for household purposes

  • mechanism equipped with grinding stone;
  • Machine connected to the power grid;
  • Bulgarian and drill (however, they are used only in the absence of harsh requirements for sharpening angle);
  • Sharpening Tips for Drill.

Each separate device is distinguished by a high level of performance, angle and easy-to-use accuracy. They have a very convenient control system with which even amateur will cope. Another additional advantage of the presented options for domestic apparatus is low cost and miniature sizes.

Ideally, the drills are necessary for a sharpening machine. However, in the absence of this equipment, you can only use a disk from it. The main thing is that the grain of the emery circle corresponds to the requirements. Round emery should be fixed on a drill or grinding. Apply Bulgarian recommended only as a last resort.

It is important to note that the process of sharpening cutting elements is accompanied by multiple risks associated with health. Therefore, before proceeding to work, your eyes should be protected, putting special glasses. Next to the hidden drill, you must put a cup with cool water in which the cutting element will be cooled.

How to sharpen different drills?

According to experts, it is necessary to start an independent practice in sharpening the drills follows from cutting products with a diameter of more than 10 mm. Sharpening angle for such elements – 120 degrees. After the procedure, the front of the drill must have symmetry. If an error occurred when sharpening, it can be fixed immediately.

At some distance from the cutting edge there is a so-called rear surface. It should be located within 1-1.5 mm relative to the cutting edge towards down.

Further, it is proposed to get acquainted in more detail with the theoretical side of the sharpening process with your own hands. First of all it is necessary to spend some training. On the surface of a grinding stone, a black marker should be drawn parallel to the axis rotation.

Next, you must properly place the drill. It needs to be kept clearly horizontally. At the same time, the markup made by a felt-tiper will be located slightly above the axis of rotation. Thus, the longitudinal part of the tool, located horizontally, will be rotated on the left side of approximately 30 degrees, which will ensure the necessary sharpening angle.

Now you can go from the theory to practice. Takes drill with a blunt tip. Next you need to find the right tool position. Initially, one side is raised, and after – the other. In no case can not be hurried. Work should flow with maximum accuracy. If suddenly the sharpened edge is heated and becomes red, it is necessary to dip the drill in water tank. Candidizing the cutting element, you can continue to work.

After finishing the sharpening of the shot drill, check the result. A drill is taken for this, a sharpened tool is inserted into the cartridge. After you can try to drill a steel surface, the thickness of which is 8 mm. If the holes are drilled without difficulty, it means that the sharpening process passed correctly.

In fact, there are many ways to sharpen cutting elements. And each individual method involves treating drills for different materials. For aluminum, copper and even stainless steel, spiral drills are used, which will appear on the universal and dual “method”. Sharpening drill for spot welding is made by grinder. Little drills with a diameter of less than 4 mm and is completely solely by hand. By the way, if necessary, you can independently sharpen the old drill under the mill.

Unfortunately, not everyone gets sharpened by the drill from the first time with their own hands. But manifesting a little patience, it will be possible to achieve a positive result.

On concrete

In the drills on concrete sharpening only rear surface. For restoration should be applied two percent or conical method.

Before you need to get acquainted with the conical method of sharpening. The cutting element is required to insert into the prism of the grinder, which moves around its axis. Next, set the parameters. The cone axis should have an angle of 45 degrees relative to the axis of drill. It remains only to activate the device and wait for the end of work. The conical method is used to create a sharp increase in the rear angle of the cutting element.

To automate the process, it is recommended to use the screw method. It is characterized by progressive movements agreed with the rotation of the grinding circle. What is noteworthy, this method allows you to simultaneously sharpen the front and rear corners of the cutting element.

On wood

First of all it is necessary to remember – this work process is very complex. The first time no one can correctly sharpen the tree drill. To proceed to self-restoration of a similar cutting element, should be accessed on a worn tool.

The main complexity of the work is that even one incorrect movement can lead to a damage. That is why it is necessary to clearly follow the prescribed instructions:

  • Near the workplace should be placed with water tank;
  • It is important to get an angle of 45 degrees;
  • drills must be kept on the extreme part of the disk;
  • So that the sharpening process passed safely, you need to put the cutting element in the washer;
  • The edges are required slightly to turn a pair of millimeters and monitor their flattened;
  • When the sharpening process will approach the logical conclusion, the machine turnover must be slowed;
  • At the end of the work, you need to cool the cutting element and check its performance.


The principle of sharpening of the metal drill is not particularly difficult, but still requires patience. Left hand need to take a tool and keep it next to the working base. Right hand need to clasp the tilt of the drill and run the rotation of the disk. The back of the edge is brought to the rotating part. With light pressure you need to turn the drill. At the same time, constantly maintain the corresponding slope. It is very important that the cutting edges get the same length and identical angles.

It remains only to check the sharpened drill.

A simple way to sharpen the drill in the video below.

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