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 the modern market you can purchase already complete sets that include products different diameters and length, 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, differing from each other in 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 general metal work. 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 out of 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. Quite a high cost, which differs 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 inserts of which are sharpened during the manufacturing process and are not subject to further regrinding, you can successfully perform drilling 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. It should be borne in mind 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 best drills for metal, the manufacturing 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.

When choosing drills of a certain type, you should proceed from how often you will need to use them 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 tool 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 are spherical;
• 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, which are becoming 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-quality ratio);
• 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.

The density of the metal is so high that special tools and mechanisms must be used to process it. To make a hole in this material, drills and drilling machines, in which the main cutting element is drills.

Which metal drills are better? It is not easy to determine, because there are universal products that would be suitable for processing all types metal products, does not exist. Experienced master will be able to “by eye” determine the type of metal and quickly select the appropriate cutting tool for processing.

A beginner in this business needs to start with the basics. First, study the classification of drills and their scope of application, because best models- These are products that are ideal for processing a specific type of metal.

What kind of drills there are, how to choose a product suitable for the job based on markings and appearance, find out in the article.

To choose the best models, you need to understand the types of drills.

Spiral

Classic, cylindrical drills, which are most often used for drilling metals. Typically, spiral products are made of HSS steel.

The material is a high-quality cutting type of steel, so the gimlets made from it are highly durable and durable.

Conical (stepped)

The cutting surface has the shape of a cone, for which this type drill and got its name. Conical drills are used to make holes in thin metal, as well as for correcting defects from other cutting tools.

The energy consumption for making a hole in this way is several times lower, due to the small contact area of ​​the tool with the surface being processed.

The advantage of using this type of drill over others is the production of large diameter holes. In this case, it is possible to obtain better quality edges than when working with spiral models.

Feathers

A special type of flat gimlet with replaceable working edges is used for drilling metal. Such products allow you to make high-quality, perfectly straight holes.

No distortion during the drilling process and the ability to make a large diameter hole in various metal structures, allows many craftsmen to abandon the use of spiral products.

The low cost of feather drills allows in many cases of metal processing to call them the best for drilling holes.

These are the main types of drills used for making holes in metal structures.

Classification of drills by material of manufacture

Which metal drills are the best for drilling particularly strong alloys is quite simple to answer:

1. To process such material, you should choose products that have a plate of increased hardness on the cutting edge. Such gimlets are the best for processing hard alloys.
2. The price of such products is low due to the fact that the main body of the cutting tool is made of ordinary tool steel.

Drills made of metal alloyed with cobalt have good characteristics.

They can withstand increased mechanical loads and excessive heat work surface while working. The cost of the products is high, but if it is necessary to make holes in a hard alloy, then cobalt analogues are the best for performing such work.

Titanium drills are not inferior in strength to cobalt drills, and when drilling alloy steels and non-ferrous alloys they show even better results.

At correct use, titanium models retain their factory sharpening for a long time, which will allow you to perform a significantly larger volume of work.

Inexpensive metal drills are made from ordinary high-speed steel P9 and P18. The cutting tool copes with its function perfectly, but the working surface quickly becomes dull, especially when a certain temperature threshold is exceeded.

Marking of cutting products

Marking drills for metal is necessary to determine the type of steel from which the cutting tool is made. The product also indicates its diameter, accuracy class and manufacturer (country). Only spiral gimlets with a diameter of less than 2 mm are not marked.

In other cases, drill markings may have the following meanings:

• P9 - made of high-speed steel with a tungsten percentage of 9%.
• P9K15 - indicates the presence of cobalt in the high-speed steel in an amount of 15%.
• Р6М5К5 - indicates the presence of a complex composition of cutting steel containing tungsten, cobalt and molybdenum.

Imported products have the HSS designation, which can be used to determine the composition of the material from which the drill was made. The HSS drill, which will be explained below, is used with an additional letter, which determines the presence of alloying metal.

HSS marking:

• HSS-E - contains cobalt. Used in processing metals of high viscosity.
• HSS-Tin - has titanium coating, which significantly increases the hardness of the working surface, and the temperature resistance of the material increases to +600 degrees.
• HSS-E VAP is a cutting tool used for processing stainless materials.
• HSS-4241 - designed for drilling aluminum.
• HSS-R - have maximum strength.

By marking the cutting tool, you can determine for what metal and in what mode the drill can be used. If the marking is not visible, then the purpose of the drill can be determined by the color of the product.

Visual identification of drill type

By the appearance of the cutting gimlet, you can determine the type of material from which the products are made and thereby find out the mechanical strength of the sample. By color you can determine the composition and quality of workmanship.

Grey

Drills gray are made of metal that has not been subjected to any additional processing.

Tool quality, in in this case, leaves much to be desired, but for one-time use such products are quite suitable.

Black

This color indicates that the tool was treated with superheated steam. During processing, the product acquires greater strength.

It perfectly tolerates numerous cycles of heating and cooling of the metal, and also maintains the sharpening of the working surface for a long time.

The price of black metal drills is not much higher than gray products, so if you have a choice, you should give preference to tools of this type when purchasing.

Dark golden

This color indicates that the cutting tool has been tempered. This type of processing significantly increases the mechanical strength of the product as a result of reducing internal stresses.

With a tempered drill, you can successfully process high-strength metals, so if you are drilling too hard alloys, it is recommended to purchase a similar model.

Bright golden

The bright golden color indicates that metal made with the addition of titanium was used in production.

Despite the high cost of such models, it is much more practical to purchase a high-quality drill than to use cheap cutting tools that complex work will need to be used in large quantities.

Thus, it is easy to determine the quality of products by appearance and decide which metal drills are best to buy.

Classification by size

To choose the best drill and not overpay, it is enough to know what length sizes these products are usually divided into. If drilling metal does not require manufacturing deep holes, then purchasing models that are too long will lead to overspending.

It is customary to classify drills by length as follows:

1. Short, 20-131 mm long. Tool diameters are in the range of 0.3-20 mm.
2. Elongated, length is 19-205 mm, and diameter is 0.3-20 mm.
3. Long series with a diameter of 1-20 mm and a length of 56-254 mm.

When performing drilling work of various depths, you should select the tool that is most suitable for the specific task.

The best manufacturers

To purchase drills and be sure that the declared characteristics are completely true, you need to choose the right manufacturer.

Companies that value their reputation do not sell products of inadequate quality. Therefore, when choosing metal drills, you should give preference to manufacturers who have been on the market for a long time.

Among the newcomers, there may also be worthy producers. But in order to find out that a good quality product is on sale, you need to make a purchase, which often represents a “lottery”.

The best manufacturing companies:

1. Bosch - products of the German company have long proven themselves only with positive side. Despite the rather high price of the products, when purchasing Bosch drills, you can rest assured of excellent quality. It is convenient and profitable to purchase tools from this company as a set.

Which drill set not to take, in any there will only be highest quality products that will last for many years, provided proper storage and use.

2. “Zubr” is a domestic manufacturer whose products are maximally optimized in terms of price-quality ratio. You can purchase the products of this company either in a single copy or in the form of a set. The latter option will significantly save money, despite the significant cost of the kit.

3. Drills Soviet made- this category of cutting tools can be classified as an “endangered species”. With due diligence, you can purchase a rarity that has unsurpassed technical characteristics.

Not only specialists, but also home craftsmen often have to process various metal products. And here you cannot do without special tools, in particular drills. And here the question arises about which metal drills are the best and how to choose them correctly.

Design and functional features

Eat different types metal drills, which differ from each other in functionality and designs. Moreover, with the help of such devices it is possible to process not only the metal itself, but also other materials, for example:

• tree;
• ceramics;
• polymer materials;
• concrete;
• brick.

Design features must be taken into account material characteristics, which will be processed. When it comes to metal drills, they include such elements as:

• cutting part - performs key work;
• shank - with its help the tool is fixed in the equipment chuck;
• working surface - it is used to remove chips from the processing area.

Classification

Depending on the design, drills for metal products are:

• spiral;
• conical;
• crowned;
• flat.

Flat tools differ in the flat shape of the working part, they are also called feather ones. Their advantages are:

• lack of sensitivity to distortions;
• simple design;
• affordable price.

However, they also have their disadvantages:

• They cannot be used to drill large diameter holes.
• There is no automatic removal of chips from the processed area.

Spiral tools

Twist type drills are the most common. This tool has the shape cylindrical rod, the assembly of which contains spiral grooves, covering its entire working part. Thanks to them, chips are removed from working area.

Depending on the design and scope of use, spiral instruments are divided into:

• Cylindrical - have general purpose. The diameter of the tools can reach 80 mm; they can be used for both home and industrial purposes.
• Left-handed - have a limited scope of use. They are needed primarily when you need to drill a bolt with a broken head or a fastener from a threaded hole that cannot be unscrewed in any other way.
• Tools of increased precision - they can be identified by the presence of the designation, A 1. With their help, you can make holes with the most accurate diameter.

Core and cone drills

Crown tools look like metal glass. On its end working part there are cutting teeth, with the help of which you can make holes with large diameter. Such teeth can be diamond-coated or made from hard alloys.

Conical products have a stepped and smooth working surface and are used to create holes of small thickness. They are able to provide at the beginning easy work centering the hole. Their key advantage- This ability to make holes of different diameters.

There are also other types of tools, thanks to which even the most highly durable materials can be processed. These are cobalt or carbide tools.

Cobalt tools made of high-speed steel, which has been alloyed with cobalt. This material gives high strength to the drill, thanks to which it is resistant to thermal or mechanical stress and deformation. They can be used to drill even high-strength and tough metals or alloys. The only drawback is the high price, which is compensated by technical characteristics.

If we talk about carbide structures, they differ in that they place on their cutting part carbide inserts, and the main part is made on the basis of tool steel. The plates are made on the basis of carbide alloys, which have high wear resistance and hardness. The cutting plates will not need to be sharpened in the future, and with the help of such a tool you can drill particularly hard metals or alloys, as well as products with great thickness.

When choosing one option or another, you should know in advance where you will use it, and also take into account the characteristics of the material being processed. When purchasing, consider the following tool parameters:

• quality of sharpening and symmetry of structural elements;
• color;
• functional features;
• material characteristics;
• working diameter;
• compliance of the form with standard parameters.

When purchasing a metal drill, you need to take into account the features of the equipment with which it will work. For example, if you need to drill into a metal product big hole, you need to take a powerful low-speed drill.

Surface color characteristics

The quality of products largely depends on the color of the surface. What does this or that color mean?

• Gray - such a tool is inexpensive and does not have the most better quality. It has not undergone any additional treatment to help increase its hardness and resistance to burning or deformation. When drilling hard metals, such a drill may not be enough even for one hole.
• Black - the tool was treated with superheated steam, has increased strength and wear resistance. The cost is higher than the previous option, affordable for most buyers.
• Light golden - after manufacturing, the tool was subjected to a tempering procedure, during which residual stresses inside were eliminated and strength characteristics were improved.
• Bright golden - these instruments are the best, they contain titanium. During operation, the level of friction is reduced, thanks to which the service life is long. The disadvantage is the high cost.

When purchasing a drill of a particular shade, think about how often you will use it, and also take into account requirements for quality and accuracy of work.

So, if you plan to use them frequently and intensively for high-quality and precise work, then it is better to purchase bright golden models.

But if you buy cheaper options for this, you will have to change them often, and in the end you will not save anything.

Dimensions

Manufacturers of these tools produce them in a wide range of working sizes. But to make it easier to understand them, you need to be able to distinguish them by series:

• short series (length ranges from 20 to 131 mm, and diameter from 0.3 to 20 mm, respectively);
• elongated (length 19-205 mm, diameter 0.3-20 mm);
• long (length 56-254 mm, diameter 1-20 mm).

Marking

Its labeling, which is not so difficult to understand, will also help you choose a particular product. Depending on the working diameter, it contains the following information:

• If the instrument has a diameter of up to 2 mm, there is no marking.
• For models with a diameter of 2-3 mm, it includes information about the steel grade and cross-sectional size.
• If the diameter is more than 3 mm, then the marking includes data on the steel grade, working diameter and an imprint of the manufacturer’s logo.

This or that alphanumeric designation of the material grade indicates not only the category of the alloy, but also about the presence of additional components in it.

For example, the letter “P” means that the product is made from high-speed steel. If there is a letter “M”, then this indicates that the composition contains molybdenum, and “K” indicates the presence of cobalt. These additional substances are designed to improve the performance of the product.

Foreign manufacturers include in their labeling more information, in particular the markings in them indicate the following:

• country of origin;
• trademark;
• alloy grade;
• working diameter;
• accuracy class;
• brief recommendations on materials that can be worked with with this tool.

Features of foreign markings

So, if we talk about the last point, which indicates the presence of recommendations on what materials are best processed with one or another tool, then such markings on foreign models are deciphered as follows:

• HSS-R and HSS-G - the product is recommended for processing steel products made by simple casting or injection molding, and those made on the basis of alloy or carbon steels with a strength of up to 900 N/mm 2, things based on metal alloys ( containing copper, zinc, nickel, aluminum, etc.) billets based on malleable or gray cast iron.
• HSS-G Co 5 - recommended for drilling metals with a strength of up to 1100 N/mm 2. These include stainless, carbon, alloy, thermally enhanced and heat, acid or heat resistant types.
• HSS-G TiAN/TiN - the working part of such products is coated with titanium, aluminum and nitride. This increases their resistance to wear and corrosion, and the tools themselves can be used for processing metals with a strength of up to 1100 N/mm 2. This includes malleable and gray cast iron, copper alloys, and steel blanks made by casting.

Which metal drills are better?

After reviewing the markings and characteristics of metal drills, let's move on to popular brands that are present on the market. It is no secret that the service life and quality of work largely depend not only on the characteristics of the product, but also on the manufacturing company.

Experts advise paying attention to the following brands:

• Brands from the CIS countries have high strength and reliability, are resistant to wear and are distinguished at an affordable price compared to foreign analogues.
• Ruko - products can have a cross sharpening and different types spraying, they can be called best example ratio of price and quality of products.
• Bosch - this brand speaks for itself.
• Haisser - the products of this brand have their own design features, special alloys are used for its manufacture. All this allows it to be successfully used even under extreme loads.
• "Zubr" is a Russian brand that offers high-quality and reliable options at an affordable price.

Rules for sharpening

If the cutting part of the drill is dull, then it needs to be sharpened. Follow these recommendations:

• Check whether the sharpening device is working properly and prepare a container with coolant.
• While sharpening, press the tool firmly against grinding wheel, start processing from the back of the cutting edge.
• The processing angle depends on the material of manufacture. For steel it is 140 degrees, for copper - 100, and for copper alloys - 120 degrees, respectively.
• As a result of the work, the entire cutting surface, including the side, must be processed.

Since there are so many different drills for working metal products on the market, sometimes right choice and it can be extremely difficult to avoid mistakes in your work. This material will allow you to choose the right tool option.

Choosing a tool for apartment renovation. Choosing the right drills.

Drill – universal tool, which is simply indispensable when carrying out repairs of all kinds of complexity. Today there are a lot types of drills, and therefore it is very important not to make a mistake and make the right choice, so that later you do not have to replace, or even simply throw away such a tool if it fails prematurely. The site will tell you how to make the right choice.

Essentially all drills differ only in their appearance (diameter and length), as well as the material for which they are intended to work and, as a result, sharpened. Accordingly, it is necessary to initially select the size of the drill (it is necessary that such a tool matches the thickness of the material that will be drilled, or self-tapping screws, anchors, etc.). Next, you should select drills depending on the work that will be carried out.

Selecting a drill for metal

Metal drills differ from conventional drills (meaning those used for wood processing) in their versatility. Such a tool is indispensable when working with metals and can be used to create holes in alloyed and unalloyed steels, cermets, cast iron and non-ferrous metals.

The most common today are twist drills for metal. As a rule, such metal drills are a cylindrical rod in which two helical grooves are made, forming cutting edges. These grooves are made at an angle of 10-45° to the axis of the cutting tool.

You should also pay attention to the material from which the drill is made. Today, the highest quality tools for metal processing are made from high-speed steel (for example, R6M5) or alloy steel (9ХС). Such drills have increased durability and strength, and also make it possible to achieve maximum results in the process of work.

Choosing a drill for concrete

Concrete is a strong and powerful material, which is very difficult to process, especially to drill a hole. As a rule, special drills tipped with tungsten and cobalt hard alloy (“win”) are used for drilling concrete. Moreover, thanks to the use modern technologies In the manufacture of cutting tools, drills made from modified tungsten-cobalt alloys have appeared on the market.

For processing brick or concrete, drills with soft or medium soft tips are used. In the same case, if you need to process granite or other hard materials (for example, the same tile), then you simply cannot do without the use of Pobedit drills with plates of medium and high hardness (in addition, a series of teeth and reverse sharpening are performed on them).

Wood drill bits: how to choose?

For wood processing modern market offers the widest selection of highly specialized cutting tools. In particular, it is simply impossible to imagine working with wood without the use of three main types of drills:

• Twist drills are a sharply sharpened metal spiral that is used to create holes in wood of small diameter (8-28 mm) but quite significant depth (300-600 mm). Thanks to its spiral shape, such a tool is very easy to remove from the work area after completing the job.
• Feather drills, as a rule, are used in cases where it is necessary to create any blind hole in wood with a diameter of 10 mm or more. It should be noted that such a drill can only be used to create holes, since due to the absence of cutting edges on the side surface, it is simply impossible to drill out what is already there.
• Cylindrical (ring, core) drills are widely used to create large diameter holes (from 26 mm). The main advantage of using such drills is the ability to obtain a neat hole without scoring or other defects, as well as high processing efficiency.

When choosing drills for work, you need to pay attention to their appearance. If we are talking about a truly high-quality tool, it should not have chips, dents, scratches or other defects. Cutting edges must be sharpened with high quality along the entire length and have a uniform color.

When choosing drills, regardless of the material for which they are intended for processing, you need to pay attention to their color - it is easy to determine from it the finishing hardening treatment that was carried out:

1. Steel gray – no treatment carried out.
2. Black – the drill has been treated with superheated steam to harden it.
3. Golden – the drill has undergone tempering treatment to relieve internal stresses in the metal.
4. Bright gold – a layer of titanium nitride is applied to the surface of the instrument, designed to strengthen it and extend its service life.

It would not be amiss to note the fact that when choosing a drill, you also need to pay attention to the manufacturer. It is best to give preference to famous companies that have been on the market for more than one year. Only in this case can you avoid counterfeits and unnecessary waste of money.

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 the cutting tool is large in size (more than 3 mm), then all possible parameters. 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 mass fraction 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).

DIN drill markings have standard parameter 338 is technical standard, which 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 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. Р6М5 – molybdenum is additionally added, increased tendency to decarbonization.
4. R12F3 – have reduced grindability, used for drilling in medium mode. Added 3% vanadium.
5. R6M5F3 – increased wear resistance, work at medium cutting speed, 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 symbol designs.