Description and selection of cone drills for metal

Drills with a cone-shaped working part are considered a professional tool that has a long term use, as well as possessing universal use and simplicity design. Externally, the drill bit like a cone, hence his name – cone. A similar type of structure makes it possible to make round-shaped holes on which there are no burrs or roughness.

Absolutely smooth hole can be applicable to perform construction and installation work, when processing metal surfaces. To properly choose the working drill, you need to carefully study its properties and characteristics.

Features and scope

The conical drill looks like its design as Step row of ring spirals. Spirals are sharpened and located longitudinally, from a wide part they narrow to a narrower under the cone. In some embodiments there is a groove, located longitudinally – it is it that forms the cutting surface of the tool. Metal cone drill is manufactured According to GOST standards. By purchasing one cone-shaped product, you can make a hole of various diameters with it. Similar versatility contributes to savings and convenience when performing installation work.

This drilling tool has proven itself In the use of high speeds of electric drills – As a result of work, smooth holes with high quality edge parts are obtained. Drill can be used for different metal sheet thickness, while it works great even on the finest fragments.

The design of the cutting surfaces is characteristic of this tool makes it possible to work with steel blanks, non-ferrous metal alloys, plastic and plastic products, with wooden and gypsum surfaces.

The working part of the drill is equipped with a pointed tip that Guarantees the exact location of the tool at the work point. Considered drills can be used not only in electric drills or screwdrivers, but also be installed on stationary type machines. If you apply a special adapter, then the drill can be fixed on the grinder or in the punch cartridge.

In addition to performing holes, a cone-shaped tool is used to correct defects, which are formed after drilling a brown. The conical drill helps to complete the completion processing, removing burrs, as well as correcting the consequences of centering disorders when drilling. This tool is often used In the process of repairing vehicles, to perform sanitary work, when finishing and building buildings and structures.

What happens?

Universal conical drill is a special device for electric tool of rotating type. The drill has a working tip in the form of a cone and a housing-shank, the end of which is processed in the shape of a hexagon or cylinder.

Cone drills are divided into 2 types.

  • Smooth – have a smooth surface of the working part, with which even durable steel can be drilled, increasing the diameter of the opening, depending on the deepening of the drill. So that the hole diameter is accurate, the drilling process is required to periodically suspend measurements. For simplicity of measurements, many manufacturers on their products apply special labels pointing to the size of the diameter of the hole.
  • Speed – This design, due to its steps, helps more accurately and simply track the passage of the drill forming the desired hole diameter. The process of drilling a stepped drill is performed more smoothly and gently.

Experienced specialists believe that when performing large volumes of works related to the drilling of holes, it is more convenient to use that cone-shaped drills, especially if the work is required on thin sheets of working billets.

The cost of the cone-shaped tool depends on the quality of the material from which it is made, as well as from the brand manufacturer. If we talk about Russian drills, they cost much cheaper than their European analogues, although in quality both products can be absolutely the same. The most popular cone drills are tools of several well-known manufacturers, such as:

  • Russian brands “Bison” and “Attack”;
  • Ukrainian brand “Globus”;
  • Japanese brand Makita;
  • German brands RUKO, BOSCH (professional segment) and Geko (household segment).

The cost of tools from these manufacturers is high, but it is justified by the impeccable product quality and the long period of its operation.

How to choose?

To select high-quality drill, experts recommend paying attention to several nuances.

  • The speed of execution of drilling, as well as the quality of the result depends on the number of steps, located on the cone-shaped working part. In addition, it is diameter, height and step of these steps. Some professional models have up to 12 steps.
  • Diameter cone depends on what size of the opening must be performed.
  • Duration of drill use and its cost depends on what material it is made, as well as from the processing of its surface.
  • In Russia, it is more convenient to use the drills that have designation of dimensions in millimeters according to GOST. Models of American producers are marked in inches, which takes over time to transfer their values ​​to millimeters.
  • High-quality drill for a long time does not need sharpening, But he must have such an opportunity.

Often, one of the criteria for choosing tool is its value. For example, Russian or Ukrainian manufacturer’s products will cost about 500-600 rubles. For the product with a maximum diameter of 20 mm, and if you take an option with a maximum diameter of at least 30 mm, its price will already be 1000-1200 rubles. The same samples of the European brand will cost 3000-7000 rubles. Based on the cost of some masters consider it more appropriate to buy several products of the domestic manufacturer than to pay for 1 European brand drill.

Solving the question of whether you need a set of tools, or it is enough to buy 1 drill, should be solved from the volume of work performed. With frequent execution of large volumes of work, it is advisable to buy a drill of good quality and those diameters that you need. To perform one-time tasks, it is enough to buy a model of the desired diameter from an inexpensive price segment.


The cone tool is marked with letters and numbers. Digital marking indicates the diameter of the cone from the minimum to the maximum, as well as the step of its steps. Letters denote the brand of alloy steel, from which the nozzle is made. The most recent figures in the marking indicate the tool on the Rockwell system.

The alphanumeric label is made from the outside of the drill by the factory using engraving. The order of the location of letters and numbers begins with the alphabetic designation of steel. Most models are made of cutting steel, so the first letter is “p”, if there is molybdenum in the alloy, the letter notation will be “MH”. Next is the numeric designation of diameters and steps.

It is noteworthy that drills made in Russia, having a diameter of no more than 2 mm, not subject to labeling.

The size

The diameter of the cone has 2 sizes. The first indicator provides information on the minimum diameter of the drill, and the second – about the maximum. The step with which the diameters change is also indicated in the marking. For example, marking 4-10 / 2 will mean that the minimum size that can be done using this drill is 4 mm, the maximum hole can be made 10 mm, and the step of changing diameters is 2 mm, that is, the drill will be diameters 4, 6, 8 and 10 mm.


Metal color from which the drill is made is the instrument quality indicator. If the drill has a gray steel shade, it means that it is alloy from which it is manufactured, not exposed to high-temperature processing, so such a product will not be durable and durable. The drills having a black color were treated with hot steam, and their strength is higher than that of silver analogues. If the tool has a golden shine, it means that its surface is covered with a layer of titanium – such a good and durable product.

The possibility of sharpening

When using it, when used, it loses its sharpness, it is not blown up, and in order to improve the efficiency of the operation, the tool is required to be sharpened. You can perform this procedure in a workshop specializing in the sharpening of the tools, or to complate the drill with your own hands. Sharpening tool performed on professional equipment, more preferable than manual version of this procedure. The choice of professional processing is based on the following reasons:

  • The diameter and the geometric shape of each cone stage will be saved;
  • The correct angle of the edge in the cutting surface is preserved;
  • Complied with the correct technological process of sharpening, which protects the tool from the recalculation.

If you sharpen a tool in the workshop is not possible, you will have to do this task yourself. During the work, you must follow the following rules:

  • Cutting parts of the drill edges must be saved the same size, Starting only the minimum part of the metal;
  • The corner of the cutting edge Cannot be changed;
  • The step between the degrees of the cone should be the same and uniform on all turns of the drill;
  • From the cutting edge to the side surface of the upper or lower coat There must be the same distance, stored on each diameter of the cone steps;
  • Tool sharpening is performed subject to its tough fixation;
  • The process is performed fixtures with small abrasive;
  • Sharpening tool must Maximum save all its geometric proportions and cutting edges.

It is easiest to sharpen the drill, if you use a special machine, a circle of baked fine-grained emery paper. How well the drill and qualitatively completed the drill is made, it is possible to determine the nature of the chip, which is obtained if you use it in.

If the sharpening is done correctly, then the chips will be the same not only in shape, but also in size.

How to use?

To take advantage of the conic tool, the electric drill will be required or a screwdriver, in the cartridge of which the drill is fixed. The choice of drill depends on the desired diameter that is planned to drill in the working part. The electric drill is best to choose with the possibility of speed control, the speed is used for operation 3000-5000 rpm.

Work on drilling hole is performed in 3 stages.

  • The drill is reliably fixed in the cartridge of an electric drill. Then on the working blank the place is scheduled for drilling hole.
  • Putting the drill at an angle of 90 degrees to the workpiece, start drilling a hole. The position of the drill at the same time should not change until the completion of the work.
  • Drilling start with small revolutions, gradually increasing their speed. When the hole is reached with the required diameter, the drilling process stops.

The result of the work will be the hole of the desired size with neat edges, without roughness or burrs.

Tips for care

Modern stepped cone-shaped drills can be used to drill holes in wood, metal, plastic and other materials. After use, the tool must be treated with a special protective composition designed to care for the cutting tool. If this composition was not at hand, it can be made independently, taking machine oil for lubrication or thick liquid soap.

If we regularly handle the cone-shaped working part, you can extend the life of the cutting surfaces, Since the above components will be able to protect them from blurring during mechanical damage arising during storage.

In the next video you are waiting for the review and test of the step drill on Metal GRAFF.

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