Need for processing various products made of metal occurs not only among professionals, but also among many home craftsmen. When performing such processing, you cannot do without special tools, one of which is a metal drill. On modern market you can purchase already complete sets, including products of different diameters and lengths, or opt for a single copy that meets the required geometric parameters and mechanical characteristics. In both cases, the question arises of how to distinguish high-quality drills from low-quality ones and choose a tool that does not have to be changed after each processing cycle due to its breakage or critical dullness of the cutting part.

Drilling metal is labor-intensive and complex process, requiring a responsible approach to the selection of cutting tools

Varieties and design features

There are various types metal drills, different from each other design features and functionality. It is important that using drills designed for metal work, you can successfully drill holes in other materials, which include:

1. wood and wood-based materials;
2. various types of polymer materials;
3. ceramics;
4. brick;
5. concrete.

The design of drills for metal work is specially developed to solve certain technological problems and taking into account the characteristics of the material for which they will be used. That is why experts advise those who do not know how to get an idea of ​​the design features of such a tool.

It is very important not to get confused in the variety of types of metal drills

Drills intended for metal processing consist of the following elements:

• the cutting part, which performs the main work of cutting metal;
• a shank with which the tool is fixed in the chuck of the equipment used;
• working surface responsible for removing chips from the processing zone.

Depending on their design, drills for metal processing are divided into several categories:

1. flat;
2. spiral;
3. crowned;
4. conical

Flat

Drills whose working part is flat are also called feather drills. Their most significant advantages are:

• insensitivity to distortions that any drill is subject to during processing with its help;
• simplicity of design;
• low price.

If we list the main disadvantages of tools of this type, they include:

• cannot be used for drilling holes large diameter;
• lack of automatic removal of chips from the processing zone (the design and geometry of such drills do not imply this option).

Spiral

Twist drills are the most common tool used to make holes in metal products. By its design, a twist drill is a cylindrical rod, on the side surface of which there are spiral grooves(one or two), covering the entire working part of the tool. It is precisely such elements of a twist drill, such as helical grooves on its side surface, that ensure the removal of chips from the drilling zone.

Depending on the design and purpose, a twist drill can belong to one of the following categories.

• Cylindrical drills for metal work general purpose. The diameter of drills included in this broad category can reach up to 80 mm. They are actively used both in production and at home.
• Left hand twist drills with very limited applications. You cannot do without them in cases where it is necessary to drill a bolt with a broken head from a threaded hole or fastener, which cannot be unscrewed in any other way. There is a simple answer to the question of how to distinguish a drill of this type from a standard right-handed one: just look in which direction its spiral groove twists.
• High precision drills. They are chosen by those professionals or home craftsmen who are interested not in good, but excellent result upcoming processing. Tools of this type can be recognized by the designation A1. They allow you to create holes whose diameter is maintained to within a fraction of a millimeter.

Crowned

Drills of this type, made in the form of a metal cup with cutting teeth on the end working part, are used to create large-diameter holes in metal. The cutting teeth of such drills can be made of carbide or coated with diamond.

Conical

This category includes tools with a smooth and stepped working surface. Used to make holes in metal products of small thickness, they provide easy centering of the hole at the very beginning of drilling, which cannot be said about a tool with a cylindrical working surface. However, the main advantage of using stepped cone drills is that with the help of one such universal tool you can produce holes of different diameters.

Among metal drills, we should highlight tools that can be used to make holes even in high-strength materials.

Cobalt

These are tools created on a base doped with cobalt. Cobalt gives the drill high strength, as well as resistance to deformation under thermal and mechanical influence. Thanks to these characteristics, cobalt-type tools are successfully used for drilling holes in products made of high-strength and tough metals and alloys. The fairly high cost of cobalt drills is fully justified by their characteristics.

Carbide

Carbide inserts are fixed on the cutting part of this type of drill. The main body of the tool is made of. For the production of plates, carbide alloys are used, which are characterized by exceptionally high hardness and wear resistance. By using such drills, the cutting plates of which are sharpened during the manufacturing process and are not subject to further regrinding, it is possible to successfully drill especially hard metals and alloys, as well as metal products of large thickness.

When choosing drills for metal, you must know exactly what technological tasks they will be used to solve, and also take into account the characteristics of the material in which you need to make a hole. To choose a tool that will meet your goals, you must also pay attention to the following parameters:

1. surface color;
2. quality of sharpening and symmetry structural elements;
3. working diameter;
4. compliance of the form with standard parameters;
5. characteristics of the material of manufacture;
6. purpose and functionality;
7. manufacturer's reputation.

When deciding which drills to choose for metal processing, you should also take into account the characteristics of the equipment with which they will be used.

So, if you need to drill a large diameter hole in a metal product, for which powerful low-speed drills are used, you will need a tool that can be used in conjunction with them.

What does the color of the drill surface indicate?

The color of the surface of a metal drill is a parameter by which one can judge the quality of the presented tool. So, different colors of metal drills mean the following.

Grey

This color has the surface of drills that are of the lowest quality and, accordingly, the lowest cost. Tools with a surface of this color are not subject to any additional processing that could increase their hardness, resistance to deformation and combustion. Please note that when drilling hard metal they may not be enough even for one hole.

Black

The surface of the drill acquires this color if it is treated with superheated steam. As a result of this treatment, the strength and wear resistance of the tool increase, and, as a result, the resource of its use increases. The cost of such products is slightly higher than gray ones, but is quite affordable for most consumers.

Light golden

This color means that the drill has undergone a tempering procedure after manufacturing. Such heat treatment allows not only to eliminate residual stresses in the internal structure of the tool, but also to improve its strength characteristics. Even in the photo, such a drill looks presentable and immediately inspires confidence in the quality of its workmanship.

Bright golden

This is the color of the best metal drills, the material of which contains titanium. Due to the content of this element in the steel from which drills are made, the level of friction during their use is reduced, which has a positive effect on the duration of their effective operation. Naturally, drills with a bright golden surface are quite expensive.

At choosing drills of a certain type should be based on how often they will have to be used for metal work. It is also necessary to take into account the requirements for the accuracy and quality of the holes that need to be created in the metal product.

For frequent and intensive use in order to make high-quality and precise holes, it is better to choose more expensive, but also the highest quality bright golden drills.

Purchasing a cheaper tool will mean that you will have to change it quite often, and this will negate the initial savings. It is advisable to choose more affordable types of drills, the surface of which is painted black or light golden in color, in cases where you need to perform one-time work related to drilling metal.

Classification by size

Modern manufacturers produce drills for metal work in a wide range of working sizes. To make it easier for the consumer to understand this variety, the corresponding regulatory document (GOST) provides for the division of metal drills into different types by size. Thus, the following categories of instruments are distinguished:

• short series, the length of which is in the range of 20–131 mm, and the diameter is 0.3–20 mm;
• elongated, the diameter of which, like the short ones, is in the range of 0.3–20 mm, and the length is 19–205 mm;
• long series, the length of which can be in the range of 56–254 mm, and the diameter – 1–20 mm.

The classification of drills depending on their length and diameter is regulated by the provisions of several regulatory documents– GOST 4010-77, 10902-77, 886-77.

How to understand the markings

Markings help you choose the right tool for drilling metal products. It's not difficult to figure it out. The marking of drills depending on their working diameter contains the following information about the presented tool.

• Miniature products, the diameter of which does not exceed 2 mm, are not marked at all.
• The markings of drills, the diameter of which is in the range of 2–3 mm, contain information about the grade of steel from which they are made, as well as the size of their cross-section.
• The marking of metal drills with a diameter of 3 mm or more contains the following data: working diameter, steel grade, and an imprint of the manufacturer’s logo.

By the alphanumeric designation of the grade of the manufacturing material, you can get an idea not only of the category of such an alloy, but also of the content of additional substances in its chemical composition.

Thus, the letter “P” in the marking of metal drills means that they are made of high-speed steel. The composition of steel alloys used in the manufacture of drills for metal work may contain additional substances that improve them performance characteristics. Such substances, in particular, can be molybdenum, which is designated by the letter “M,” and cobalt, designated in the labeling by the letter “K.”

Foreign manufacturers include more detailed information about the presented instrument in the labeling. Having decided to purchase such drills, you will receive the following data from their markings:

• name of the country of origin;
• manufacturer's trademark;
• steel alloy grade;
• working diameter of the tool;
• accuracy class;
• short recommendations on materials that such a tool can drill.

Popular brands of instruments from foreign manufacturers

In order to know, when choosing foreign-made drills, which ones are better suited for solving certain technological problems, it is enough to have an idea of ​​the material that will be processed with their help. So, foreign manufacturers give the following recommendations for choosing a tool with a specific marking.

HSS-R and HSS-G

Using tools marked as follows, it is recommended to drill:

• steel parts manufactured by simple casting and injection molding; products made of carbon and, the strength of which does not exceed 900 N/mm 2;
• products made of metal alloys containing aluminum, graphite, copper, nickel, zinc (bronze, brass, cupronickel, etc.);
• blanks made of gray and malleable cast iron.

HSS-G Co 5

Drills with this marking can be used for processing metals whose strength reaches 1100 N/mm 2. Such metals, in particular, can be the following steels:

• carbon;
• stainless;
• thermally improved;
• acid-, heat- and heat-resistant;
• alloyed.

HSS-G TiAN/TiN

If such a designation is present on metal drills, this means that titanium-aluminum-nitride coating is applied to their working part. This coating significantly increases the resistance of drills not only to corrosion, but also to wear, which helps to increase their service life. Tools with this marking can also be used for processing metals and alloys with strength reaching up to 1100 N/mm 2. Manufacturers recommend using the following types of drills for processing:

• malleable and gray cast iron, in the structure of which graphite inclusions have a spherical shape;
• copper-based alloys (brass, bronze, cupronickel);
• steel blanks produced by casting (including injection molding).

The best manufacturers

When choosing a tool for creating holes in metal, it is important not only to know what types of drills there are, but also to understand the brands presented on domestic market. Both its durability and the results of the processing that will be performed with its help depend on who exactly made the drill.

• enterprises that produced drills in the territory of the former Soviet Union(their products, of which there are fewer on the market every year, are distinguished by high strength, reliability, wear resistance and, accordingly, durability);
• Ruko (drills produced under this brand can be made with cross sharpening and various types spraying and are characterized by an excellent price-to-price ratio high quality);
• Bosch (the very brand under which such drills are produced already says a lot about their exceptionally high quality and reliability);
• Haisser (drills of this brand, due to the peculiarities of their design and the use of special alloys for their manufacture, are able to successfully cope with their tasks even under extreme loads);
• “Bison” (under this domestic brand, affordable, but high-quality and reliable drills for metal work are produced).

How to sharpen

In order to efficiently sharpen a drill if its cutting part becomes dull, you must adhere to the following recommendations.

Metal drill markings are special designations that are indicated on the cutting tool. It is imperative to pay attention to all the indicated numbers and letters in the marking, as they indicate the diameter of the device, the grade of steel from which it is made, the accuracy class, as well as the country of origin or brand of manufacture. Drills that have a diameter less than 2 mm are not marked; products whose size is from 2 to 3 mm are marked with diameter and steel grade. If cutting tool large size (more than 3 mm), then all possible parameters are indicated on it. It is necessary to know the marking features in order to select drills of the required size, since not all devices are suitable for drilling certain holes.

Twist drill markings: meaning of letters

Solid spiral cutting tools made of high-speed steel have the following grades: P 9, P18, P9K15. The letter P means that the product is made of high-speed steel. After the letter P there is a number that indicates the amount of tungsten that the tool contains. The average is taken. More letters and numbers follow. The numbers that are indicated after the letter indicate the content of the alloying substance in the alloy; this is a percentage parameter indicating the mass fraction of the substances. For example, if K6 is indicated, this indicates that the alloy contains six parts of cobalt, which helps to increase heat resistance. If M4, it means there are four parts of molybdenum. That is, after the letter P and the number, a special letter (the name of the element) and a number (the amount of the element present in the alloy) are indicated - this is the percentage content of the alloying element.

photo: marking of a twist drill for metal

For example, the following marking is indicated: Р6М5Ф3. This means that the drill is made of high-speed steel with the addition of 6 parts tungsten, 5 parts molybdenum and 3 parts vanadium.

Important: the labeling does not indicate the quantitative addition of chromium or carbon, since the first element has a stable parameter of 0.4%, and the second has a value equal to the vanadium content.

An example of a symbol for a spiral tool with a cylindrical shank.

A device that has increased accuracy, diameter - 15 mm, version 1, accuracy class A, designated: 2300-7066 A1 GOST 886-77. IN given value indicates the accuracy class of the device. It can be A1 - increased accuracy or B1 - normal accuracy. 2300 – operational and design characteristics, 7066 – serial number manufacturing. GOST - in accordance with what standards the device is manufactured.

If you purchase an elongated spiral drill with a cylindrical shank, then AB 2300-0055 will be written on it. AB is the enterprise index, 2300 is the operational and design characteristic, 0055 is the serial number of the standard size of the device according to the factory standard.

An installation with a conical shank has an indicator of 2301; for solid ones, the manufacturer’s trademark, diameter, grade of carbide, and the letter “T” must be indicated if the installation has increased accuracy.

Imported devices are designated HSS or DIN. The HSS device has an additional marking - a letter that indicates the working material. For example:

• HSS-Co (addition of cobalt);
• HSS-E (cobalt addition);
• HSS-G (addition of metal P4M3 - molybdenum);
• HSS-R (addition of metal P2M1 - molybdenum).

The marking of DIN drills has a standard parameter of 338 - this is a technical standard that fully complies with GOST 10902-77.

Center drill designation

The designation of centering drills is established according to GOST 14952-75. The designation has an additional letter A, B, C or R.

1. A and B indicate that the design is used for 60 degree openings and has (B) a safety cone or does not have one (A).
2. C – used for 75 degree holes without a safety cone.
3. R - for holes that have an arcuate shape.

photo: marking of a centering drill for metal

The installations have a designation, for example, 2317-0118 GOST 14952-75. 2317 is an operational and design characteristic, 0118 is the serial number of the standard size of the device according to the factory standard.

For example, if the number 0001 is indicated, then the diameter is 1 mm. Devices of group B have marking features. 2317-00-12 if this is the second version, and 2317-0113 if this is the first.

Group C is designated: 2317-0022 (second version), 2317-0124 (first), group R 2317-0027. This is if the diameter is 1 mm.

Marking of drill р6м5 в this type devices may not be specified.

Marking of the feather cutting tool

Strength is indicated:

1. P18 is a satisfactory indicator, increased grindability, indicating a wide range of quenching temperatures.
2. P 9 – characterized by increased wear resistance, a narrower range of hardening temperature indicators, and increased ductility.
3. P6M5 – molybdenum is additionally added, increasing the tendency to decarbonization.
4. R12F3 – have reduced grindability, used for drilling in medium mode. Added 3% vanadium.
5. R6M5F3 – increased wear resistance, work on average speed cutting, used for carbon and alloy tool steels.
6. R9K5, R6M5K5, R18K5F2 – cobalt is added, which provides increased secondary hardness, heat resistance, and increased cutting conditions.

They have the designation 2304 - operational and design characteristics. Full marking 2304-4001-50-108. The indicator from 50 to 108 may vary. He points to possible meaning diameter

Conclusion

Each device must indicate the steel grade (P and number), additional elements included in the composition (M, K, F and the number - percentage), the diameter of the drilling part, as well as the trademark of the manufacturer. In order to choose the correct size device, pay attention to these parameters, as well as to the design symbol.

People often call this instrument “carrot” because of its similarity to this vegetable (perhaps there really is a similarity, they are very similar in shape).

What is the versatility of this drill? And its versatility lies in the fact that it is tapered and has sections marked along the length of the barrel.

Designed for drilling holes in plastic, wood, metal and other materials.

I’ll say right away that it won’t take thick materials, but thin materials up to 5 mm are just right. Very convenient when you need to drill several large diameter holes, for example 10 mm and 26 mm. This is done with one such conical step drill without many additional drills and replacing them in the drill chuck.

Let's take a closer look step drill device, characteristics, and also they can be applied.

Why do you need a step drill for metal?

Any craftsman must have such a tool as a drill, so that when performing this or that work he will be able to drill holes of the required size in certain materials - wood, concrete, brick, plastic, metal. Currently, the market offers specialized drills - designed for processing a specific material. Each of them has unique characteristics and features inherent only to it.

The main characteristic of any drill is its diameter. It determines what size hole can be drilled in a certain material.

Today dear friends I want to bring to your attention a universal drill that can successfully replace conventional drills.

Intended for metal processing, this drill has a non-standard shape. It also stands out because it provides, without any additional accessories, the ability to drill neat and precise holes on the surface of any material.

For many craftsmen, working with this drill will be new. They differ from others in the quality of drilling, even if the metal is very thin.

Those who have tried it at least once drill a hole in metal up to 1 mm thick, they will understand: firstly, the drill begins to walk along the surface, and secondly, it begins to bite the edge and the hole no longer turns out to be round, but triangular.

With their help you can drill holes in plastic, pipes, wood, and drywall. In this case, you will not need to use a centering device, which will significantly simplify the work.

This tool is often used to grind an already made hole. With its help, you can quickly remove chips formed around the edges, so there is no need for a needle file or sandpaper, which are used to process holes by hand.

The stepped drill has a special structure that looks like progressive channels. Each subsequent channel has a larger diameter than the previous one. In this case, the transition between them is made at an angle of 35-45 degrees. This feature provides a significant increase in the efficiency of processing thin metal (at the level of 50%).

I purchased this tool on the Aliexpress trading platform. The set included three drills with different number of steps and different diameters. The first drill has five stages from 4 to 12 mm. The second drill has nine steps from 4 to 20 mm. And the third (the largest) has 15 steps from 4 to 32 mm.

In each of them the step pitch is 2 mm. The step pitch is the diameter of the next largest section, that is, each subsequent step increases the diameter by 2 mm. For example, if in our example the drill is 4-32 mm with a step of 2 mm, then we get 15 steps: 4, 6, 8, 10,... and so on up to 32 mm.

Design and characteristics of a cone-step drill

Let's look at the design of the drill itself. The sharp tip with which this product is equipped easily penetrates any metal, no matter what its density. At the same time, the absence of the need to use centering devices significantly simplifies the process of drilling holes.

Using a conventional twist drill with a diameter of 9 mm or more to process thin metal, you are guaranteed to encounter difficulties. The primary problem will be the impossibility of its precise centering. This is due to the fact that its tip is very large. But in order to achieve the goal using this tool, you will have to first drill a smaller hole, and then enlarge it to the required size using an existing conventional twist drill.

Additional convenience of using a step drill is provided by the diameters of its thickenings marked on the sections, so you will not need to use a caliper to determine them.

The non-standard structure of this tool makes it possible to drill round holes that have different diameter in products made of different metals - steel, including stainless steel, aluminum and others.

You need to know what is intended for drilling holes in thin sheet metal, the thickness of which does not exceed 4-5 mm. The special structure of the tool prevents the occurrence of burrs and provides the ability to grind a finished hole.

From the front, this tool looks like a cone with two cuts. They perform the function of cutting metal - drilling it. After moving to the next stage, a hole chamfer, which was drilled by the previous step.

The tool shank is hexagonal, which ensures best mount in the cartridge.

Please do not confuse the concept with each other step drill and cone drill. They differ from each other in the design features of the working part. The conical drill has a head with a smooth surface, the stepped drill has a special marked steps who have cutting edges. Using a step drill, the diameter of the drilled hole can be selected based on the markings of the sections, rather than relying on the “eye gauge”.

Different types of steel are used to produce these tools. The most optimal choice will become a drill marked HSS. It indicates that it can be used to process metal at high speed and at the same time it will not deform even with strong heating.

One of the advantages is the ability to drill holes, with different sizes diameter using one tool. No need to change drill bits to do this job. The drill got its name due to its appearance– a smooth transition to the next diameter is ensured by a cone-shaped part made in the form of a step, which allows you to change the size of the hole without stopping work.

This provides increased convenience if you need to drill a hole of a certain diameter or match it to a cone. Step drill for metal Compared to other products with a similar function, it has a number of advantages.

Advantages of step drill

Many craftsmen wonder: is it rational to buy such an expensive tool? After all, the selling price of this product can vary up to 2 thousand rubles, or even more. It is directly influenced by the material of manufacture, the level of strength, the type of coating applied to the working part and other characteristics that are a priority when choosing a drill.

In general, friends, you can write for a long time about how cool the drill is, the instructions even say that the coating is made of titanium nitride (which I doubt, of course, it’s China after all), but for myself I emphasized the following REAL advantages:

1. 1) allow you to work with wood, metal, plastic and other materials. Hole diameter The diameters that can be drilled with them range from 4 to 32 mm (the step between them is 2 mm);
2. 2) the tool is truly universal, since the master does not need to purchase a set of single drills in order to drill holes with different diameters;
3. 3) diameter markings on the body– convenient and practical, eliminating the need to use a caliper to measure them;
4. 4) maximum thickness of material that can be worked with this drill, is 5 mm. The edge simply won't allow it anymore. But if you need to make a through hole required diameter in metal up to 10 mm thick, then you can be smart and drill a hole on both sides;
5. 5) the tail has a hexagon shape, and this ensures better reliability its fastening in the cartridge electric drill or a screwdriver.

Why does an electrician need a step drill for metal?

Friends, we have got to the very essence of the question that you probably had a long time ago while reading the article: Why does an electrician need a step drill for metal?? What does it do to them, since it essentially only works with wires?

But I assure you during the process of installing electrical wiring, such a tool will be very useful for an electrician.

As an example, I can cite the need to drill holes in a metal profile for pulling inside plasterboard construction wires The thickness of this profile is about 0.5 mm. The diameter of the corrugation that needs to be threaded into the profile is 16 mm. You cannot drill through such thin metal with a regular drill; it will immediately begin to bite and tear, resulting in uneven holes.

And with a step drill you can drill a profile without any problems, and of the required diameter - 16 mm, 20 mm, 25 mm.

Another example where this tool can be used is in electrical panels. Sometimes it becomes necessary to make an additional hole in the shield. For example, for various control buttons, light bulbs, cam switches, oil seals, locks and other accessories.

Real example how to drill through metal with a step drill. Thickness of the given metal electrical panel is 1 mm.

Installation of all these devices also requires drilling holes of considerable diameter in the shield body.

And finally, you can use a step drill to drill holes in various boxes and cable trays to remove wires and cables.

I also came across a distribution box in which the holes for cable outlets were rigidly fixed, that is, they need to be drilled out in order to install a gland or rubber plug. You can suffer and “hollow out” everything with a knife, but why? This universal tool will also help us cope with this task.

From this we can conclude that it is an easy-to-use tool that is guaranteed to be useful in the household.

From myself personally I can only leave positive feedback about this tool. In accordance with the price and quality, it is worth the money, and if used wisely, it is a quite suitable tool. Therefore, if you buy it, you will not only not go wrong, but also win.

Metal drills are two-pronged cutting tools, the teeth of which have a wedge-shaped body, which is limited by the presence of a front as well as a back surface. Used for machining holes on drilling machines. They form holes in different materials and are made of high-speed, alloyed material. What types of drills are there? Spiral, feather, centering, deep drilling, grooved and annular drills. When choosing the necessary cutting tool, first of all, you need to pay attention to its performance qualities, for example, the material of manufacture, heat treatment features, and sharpening angles. Therefore, it is extremely important to know what better drill on metal.

Criteria for determining the best metal drills

First of all, you need to pay attention to the sharpening angles of the cutting part. The geometric parameters of the cutting part of the tool include rake angle gamma, clearance angle alpha, tip angle 2 phi, cross edge angle psi and helical flute angle omega. The choice of inclination depends on the characteristics of the surface.

Back tilt settings affect tool life. Alpha in devices reduces the work of friction and the intensity of wear on the rear surface. But if it is too high in the device, then the heat dissipation of the object deteriorates, and the strength of the cutting part also decreases.

The vertex angle of 2 phi affects the possibility of processing the material, whether it be steel, stainless steel, cast iron, brass, aluminum alloy, copper or marble. By the way, you can order a marble window sill here.

The tilt parameter affects such features of the cutting tool as:

1. Durability

2. Ability to process various materials

Also choosing best drills for metal, it is necessary to take into account the features of the cutting process, speed, chip yield, device diameter and the specific application of each device.

Some of the most important parameters are:

• Service life (an important parameter for a tool, as it affects the quality of the device and the duration of its use);
• Operating mode of the tool (features of its marking);
• The way the drill looks is the color (black ones have high wear resistance due to the use of superheated steam, golden ones are durable and have reduced friction thanks to a layer of titanium nitride, gray ones last for the shortest possible period, since they are not treated with anything).

A high-quality drill should be made of high-speed steel, which contains molybdenum and tungsten. You should not choose gray devices, as they have a very short service life. The way a metal drill looks like is one of its most important characteristics.

Manufacturers of metal drills

When choosing a tool, it is important to pay attention to the nomenclature and labeling of the device from each manufacturer. The marking depends on the diameter of the installation. Up to 2 mm, structures are not marked; up to 3 mm, the steel grade and diameter are noted. Larger instruments carry information about the manufacturer, and they are also marked with an accuracy class.

The marking begins with the letter P, which means high speed steel. The numerical value indicates the content of various substances in the alloy. For example, K6 means that the alloy contains cobalt, MZ - that there is molybdenum. If you purchase an imported unit, the marking will be in the form of the following values: HSS or Din.

Among the high-quality cutting objects, the following manufacturing companies are distinguished:

1. Ruko;
2. Bosch;
3. Nachreiner;
4. Guhring;
5. Werko

Ruko drills model range TL 3000 stands out on the market due to its reasonable price and high quality material. Drills with a diameter of 3 mm are designated Din 1412 C, as well as a sharpening angle of 130 degrees. Manufactured using titanium nitride and titanium aluminum nitride coatings. They are used for drilling great depths, as they have a set of multi-purpose designs.

• The HSS-G range is suitable for drilling carbon and alloy steel, cast iron, as well as copper and aluminum alloys.
• HSS-E also drills stainless steel and acid-resistant steel, copper and aluminum alloys.
• HSS-G Tin and HSS-G TiAIN are suitable for drilling all materials plus titanium alloy.

Bosch drills are distinguished by an oxide coating, which removes chips when drilling, and have a mesh grinding with a sharpening angle of 135 degrees, which is suitable for any material. They have high strength and heat resistance due to cobalt alloying, cope with difficult production tasks, have an h8 accuracy class, and a tensile strength of 1000 N/mm 2.

Nachreiner, Guhring, Werko drills are devices from foreign manufacturers (Germany), which are manufactured according to all the most important standards, they are the most expensive, their cost starts from 300 rubles.

You should not choose structures made in China, even though they are the cheapest, as they are characterized by increased fragility, low tensile strength, and a short service life.

Conclusion

When choosing the cutting tool you need, be sure to pay attention to the manufacturer, as well as the main technical specifications and selection criteria (service life, operating modes, material processing). By choosing the best drill, you will be able to use it efficiently for a long time.

Which are the best drills for metal: Video

Modern drills and drill bits allow you to make holes of the required diameter in almost any metal or less durable material. Types of drills The store shelves are full of not only different labels, but also different quality. Let's figure out how not to make a mistake when buying a drill.

1 Types of drills and their purpose – we conquer metal!

The classification of drills is quite complex and takes into account many factors: purpose, design, shape. If we divide them into two initial groups, we get drilling tools for metal and drills for wood or other soft materials. Types of metal drills are distinguished by the presence of two longitudinal grooves that divert chips to the side, as well as a special sharpening angle. However, core and cone drills for metal fall out of this series.

Core bits are used for drilling large holes and working with multilayer materials, while they do not particularly depend on the power of the tool - the structure of the tool allows you to work even with conventional drills, since the cutting forces are relatively small. When choosing crown products, you should pay attention to the shank - it must be powerful and durable to prevent slipping in the chuck. Vibrations, overheating - these two factors affect the wear of the tool; by getting rid of them, you will significantly extend its life.

Cone drills confirm their name by their shape - it allows you to drill holes of arbitrary diameters, depending on the needs of the master. The operator only needs to mark the diameter of the circle and accurately determine the drilling center. Conical products with smooth walls require constant control over the drilling process, while stepped products facilitate work where it is necessary to drill holes of a certain diameter, which corresponds to one or another step.

2 Wood drills – a set for all needs

Conventional twist drills with a single flute for chip removal are designed for woodworking. The products are presented in a very impressive range of diameters - from 3 mm to more than 50! If this diameter turns out to be insufficient, ring products will come to your rescue; they are also called crowns - not to be confused with core drills for metal! Rings look like rings with teeth, with a center drill.

The disadvantage of such products is that they cannot make particularly deep holes - ordinary tools can reach a depth of up to 20 mm, professional tools - almost 70 mm. The same drills are also used when working with other soft materials, for example, plastic. The thinner the tool, the shorter they should be - the laws of physics cannot be canceled, a thin and long drill will break even with slight pressure. Thicker products can reach a length of more than half a meter - this is just for the case when you need to make a very deep hole.

Please note that drills for deep drilling will weigh a considerable 2 and even 3 kilograms. With an ordinary household drill, even short-term work will seem like a serious test, however, it is not a fact that such a drill will be able to turn the tool even at idle. Feather drills for wood represent a compromise between length and weight. Drilling occurs due to the thickening of the rod in the shape of a feather. The length of the rod is not particularly limited. For this advantage you have to endure a disadvantage - the lack of chip removal.

Forstner drills are ideal for creating blind holes (not drilled all the way through). They allow you to make a hole with a perfectly flat bottom. The diameter of the resulting holes can reach 50 mm, and the length of the products usually ranges from 10-15 cm, although there are also special extensions.

The same laws exist for all drilling products correct use- how larger diameter, the lower the number of revolutions should be set on the drill, the harder the material, the fewer revolutions, the longer drill, the less you should press it.

3 Drill markings: deciphering the designations

The marking of drills for metal and wood is influenced primarily by their diameter. Thin products are produced without any marking at all - the diameter and grade of steel are indicated on tools from 3 mm and above. The thicker the drill, the more information should be indicated on it: accuracy class, manufacturer...

The letters and numbers printed on the product are easy to decipher. Traditionally, the marking of products produced by domestic factories begins with the letter P - this is how high-speed steel is designated. The number that follows indicates percentage tungsten The following symbols indicate mass fractions other elements. Cobalt is designated by the letter K, molybdenum by the letter M. The more such elements in the composition, the better the product can withstand temperature and mechanical loads.

Traditionally, the percentage value of carbon and chromium is not marked, since in the first case the element content is always proportional to the vanadium content, and in the second case the percentage is always the same - 4%. If the vanadium content of the steel is more than 3%, then the letters F and a number indicating the amount will appear on the drill.

For imported products, completely different markings are used - DIN and HSS. DIN drills are multi-purpose tools that are suitable for both general work and deep drilling. They work best with metals that produce medium to long chips. Products may have different coating, which is easy to recognize by its colors.

HSS drills are distinguished by the letters that follow the abbreviation. So, the letter G indicates that this is a tool that can easily cope with carbon and alloy steels, cast iron, aluminum and copper alloys. E are drills that, in addition to alloy and carbon steel, will drill acid-resistant and stainless steel.

For titanium alloy, which is known for its strength, HSS-G TiN and HSS-G TiAlN are suitable. Of course, all of the above metals are also tough for them. Choose tools from trusted manufacturers - good drills are made in Germany, France, the Baltic countries, and there are many worthy ones among domestic manufacturers. Products from China are traditionally inferior in quality, although they are more affordable.

4 What the color of the metal tells you – choose a set!

The color of a product can tell a lot about its capabilities, no matter what kind of drill we have in front of us - for wood or for harder materials. For example, gray inherent in the simplest drills without any processing - this is the color of the steel itself. The black color of the surface of the product indicates that the drill is finishing exposed to superheated steam. Such tools have more long term operation.

A yellow tint indicates the metal tempering procedure. This procedure relieves internal tension, which becomes excessively fragile. Thus, manufacturers are trying to achieve a golden mean - hardened products have a high strength, but at the same time are quite fragile. But if you reduce the internal stress by slowly and long-term heating of the metal, the tool will become somewhat softer, but will retain high degree fortresses

Bright golden color indicates best products who can cope with the most complex work. What makes the drill golden is a layer of titanium nitride, which significantly reduces friction and increases strength. Of course, such tools are not cheap.