Not only professional builders, but many home craftsmen periodically have the need to process various shaped parts. This kind of work can only be done if there is available suitable tool and metal drill the required section and shapes. Those who are often faced with the creation of various parts for assembling metal structures prefer to immediately purchase entire sets of metal drills. For a single case, it is rational to buy only one type of drill. But in both situations, the question arises, which metal drills are better, more reliable, stronger, so that you don’t have to change them after each individual block of work. You will learn about all the nuances of choosing such a tool from this article.

It is not difficult to understand which metal drills are better. Follow these criteria and check out the features of the tool that meet these requirements:

• shade;
• quality and symmetry of sharpening;
• diameter;
• standard form;
• quality and type of metal;
• purpose and capabilities;
• manufacturer.

Important! If you, before buying metal drills, clearly define your goal and indicate the price of the issue, choose the right tool it will be very easy to work with.

In addition to these characteristics, be sure to take into account the fact of what kind of drill you have. For example, if you need to punch holes of a large cross-section, then you will need drills of the same diameter and length, and only powerful and low-speed drills are suitable for this. In addition, some drills can only be used with coolants so that they and the metal being processed do not burn. An exception may be a situation when you use drills of a smaller cross-section sequentially, expanding the holes in several stages to the desired size.

Drill color

The first criterion by which you can independently determine the quality of the instrument offered to you is its appearance, in particular, color. Experts note the following features:

1. Grey. If the metal looks exactly this shade, then you are being offered the most unreliable option - these drills have not undergone any treatment to harden and increase resistance to deformation and combustion. Yes, the price of such a metal drill will be very low, but it’s good if it’s enough for you to complete one task.
2. Black. If the drill is black, this indicates that it was treated with superheated steam. The result of this procedure is an increase in strength characteristics and, as a result, an extension of service life. The price of such products is slightly more expensive than tools gray color, but quite accessible.
3. Pale golden hue. Metal drills acquire this color after tempering has been used during the manufacturing process. The main purpose of this treatment is to relieve internal stress in the hardened metal and increase its strength.
4. Bright golden color. These drills will cost you much more, but the alloy will contain the most durable titanium available today. This reduces the friction of the drill during operation, making making holes much more convenient and extending its service life.

Important! Determine which are the best metal drills for you, approaching the purchase issue from a practical point of view. If you constantly need this tool, you should not save - as a result, you will spend more time on the entire drilling process, on purchasing a new tool after a short time, and you will hardly be satisfied with your purchase in terms of the quality of the result. In this case, there is only one way out - to buy drills of a bright golden hue. For single jobs, cheaper black metal drills or those with a light golden color are quite suitable.

Metal drill sizes

The size chart is quite wide, may vary depending on different manufacturers various parameters. But there is also a certain classification according to the current GOST, which distinguishes the following groups of metal drills:

1. Short. This category includes instruments whose diameter ranges from 0.3 to 20 mm and length from 20 to 131 mm.
2. Long drills for metal. This group is represented by products with cross-section parameters the same as short drills, but with a length from 19 to 205 mm.
3. Long. This category includes metal drills with a diameter ranging from 1 mm to 20 mm inclusive, with a length of 56-254 mm.

Important! All requirements meet GOST 4010-77, 10902-77 and 886-77, respectively, the above list.

Marking drills for metal

The marking of metal drills is determined by their diameter, as well as where they were made. The following rules and features can be noted:

• Drills with a cross-section up to 2 mm are not marked.
• Drills with a diameter of 2-3 mm - on them you will find designations of steel grade and section.
• From 3 mm - data such as cross-section, metal grade, including additional substances in the alloy, and the manufacturer’s imprint are applied.

Important! The drill marking is an alphanumeric combination that is quality products includes:

• letter P - designation of high-speed steel;
• alphanumeric combination - indicates the content of other metal impurities in the alloy, for example: M3 - molybdenum, K6 - cobalt.

Domestic manufacturers are limited only by these labeling rules. If you decide to buy metal drills from imported brands, you will find more detailed information on quality products:

• name of the country of origin;
• company trademark;
• grade of steel or alloy;
• drill section and size;
• recommendations for use - metal that can be processed with one or another drill;
• accuracy class.

Important! Imported drills are marked with HSS or Din type values. To make it easier for you to understand these markings and choose the right tool for you, below are recommendations for the use of some of the most popular types of alloy with this marking.

Alloys, markings, purpose of metal drills

You can figure out exactly what kind of drill you need on your own if you know what kind of metal you need to drill. Manufacturers' recommendations are as follows:

1. HSS-R and HSS-G. Metal drills with this marking are intended for processing:
   • steel - cast, injection molded, alloyed, carbon, with strength up to 900 N/mm²;
   • metal alloys - aluminum, cupronickel, graphite, bronze, brass;
   • cast iron - gray and malleable.
2. HSS-G Co 5. If drills are marked as such, the strength indicator in this case is limited to 1100 N/mm². They are appropriate to use for steel:
   • stainless;
   • carbon;
   • thermally improved;
   • acid and heat resistant;
   • alloyed;
   • not heat resistant.
3. HSS-G TiAN/TiN. To make tools from this type of metal, titanium-aluminum-nitride sputtering is used. As a result, the surface becomes resistant to corrosion, cuts metal perfectly and can remain in its original form for a long time. They are suitable for machining alloys of various origins with strengths up to 1100 N/mm². The list of recommended metals includes:
   • cast iron - gray, with spheroidal deposits of steel, graphite, malleable;
   • alloys - cupronickel, brass, bronze;
   • steel - cast, including under pressure.

In addition to these steel grades, other metals are also used to produce drills:

Types of metal drills - body and tip shape

The variety of the current range of metal drills is very large. To a greater extent, this happens because they are used not only for their intended purpose - for drilling metal, but are also often used for other types of processing work:

• wood;
• plexiglass;
• ceramics;
• plastic;
• concrete.

Important! Each type is suitable for a certain range of work due to the fact that the design is developed in a special way, taking into account all the nuances of a particular material.

Drill design

The main elements of the drill are:

• cutting part;
• shank;
• working surface for removing chips from the hole.

There are 2 main groups of drills for metal based on these characteristics.

Flat drills

Otherwise they are called feathers. Models may differ in the shape of the sharpening of the cutting surface. Main advantages:

• absolute insensitivity to distortions during work;
• simplicity of design;
• cheapness.

Flaws:

• diameter reduction work surface during sharpening;
• there is no automatic removal of chips from the hole.

A commonly used variety is cone drills for metal. They are available for sale individually and in whole sets with a cross-section in the range of 6-60 mm. A conical metal drill is more intended for use on special equipment - a drilling machine or a two-handed drill. The name speaks for itself - the shank is sharpened in the shape of a cone. Excellent for making large cross-section holes.

Twist drills

These metal drills are more popular today and it is their varieties that are found wide application. The shape is cylinder-shaped rods, with 1 or 2 grooves-grooves running along the entire surface. With their help, chips from the hole are immediately removed outside during operation. Depending on the shank of the metal drill, there are:

1. Conventional cylindrical drills for metal - usually their diameter does not exceed 12 mm. Suitable for both professional needs and everyday tasks. This group is the most popular type of metal drills.
2. Core drills for metal. Metal drills with such a shank are used when it is necessary to make big hole- with a diameter of 30 mm. This tip looks like a crown with frequent teeth, most often shaped like a hexagon. These drills are more suitable for thin metal.
3. Drill for thread. This model of the tool has a direct purpose - to design a hole with a thread of the required section. The diameter of the drill itself is usually taken at 1 unit is millimeter smaller than the hole cross-section.
4. Step drills for metal. This type is universal in that with one tool you can make holes of various diameters. The only caveat is that they are recommended to be used only for sheet material, the thickness of which does not exceed 2 mm. The diameters of such drills for metal can be up to 30 mm. Price - increases as the section increases.
5. Left hand drills. Their scope of application is limited - only for unscrewing hardware: screws, bolts, self-tapping screws.
6. High precision drills. These tools are chosen mainly by those for whom it is very important high accuracy result. The accuracy class is indicated by an alphanumeric combination - A1 or B1. The higher the accuracy class, the higher the price of metal drills.

Drill manufacturers

Very important point when purchasing metal drills - the manufacturer. The fact is that good consumer reviews and optimal price- these are not all factors. The reliability and credibility of the brand affects the quality of sharpening, the strength of the alloy, wear resistance, anti-corrosion and fire-resistant properties of the tool. Therefore, do not try to save a lot, give preference to trusted companies whose products will serve you for more than one task.

According to reviews and market positions, metal drills are considered the best:

What else do you need to know about metal drills?

After a certain service life of any drill, it must be sharpened. You can do this procedure yourself under 2 conditions:

• you purchased a tool from a reliable manufacturer who does not skimp on the quality of the metal;
• you follow the rules of sharpening technology.

You will be able to complete self-sharpening drills, if you follow this pattern:

1. Be sure to put on protective clothing - goggles, gloves - before starting work.
2. Prepare containers with coolant. For this purpose, you can use water or machine oil.
3. Check the serviceability of the sharpening apparatus.
4. Press the drill bit firmly against grinding wheel and treat the surface sequentially, starting from the back.
5. Stick to it suitable angle sharpening:
   • steel - 140 degrees;
   • bronze - 120;
   • copper - 100.
6. Process the working part of the drill while maintaining the sharpening angle.
7. Do not concentrate exclusively on the tip - the entire surface, including the side, must be well sharpened.

Important! Before you immediately sharpen the tool you need, first practice on those tools that you definitely won’t need anymore. This way you can get the hang of it and do everything correctly with the drill you need.

Video

Watch the video, which clearly shows how you can sharpen a drill yourself.

Conclusion

Now you know everything about how to choose the right drill bits and which ones are best for your purpose. Take into account all the criteria when purchasing a tool and then you will not have to worry about the need to purchase a new drill in the near future. It will serve you for a long time, and the quality of the work performed will meet the specified requirements.

Drill set various holes at most hard materials, a high-quality metal drill is capable of not becoming dull or breaking. Tall performance characteristics you can expect from a drill if it is correctly selected for the product being drilled, made of quality material and sharpened as necessary.

Let us consider in detail the types of metal drills, their characteristics, features of use and criteria for choosing a cutting tool.

A metal drill is an indispensable tool for a modern builder

A metal drill is used for cutting holes in alloyed and unalloyed steel, its alloys, non-ferrous metals, cast iron and other types of metal. Often such drills are used when working with hard plastic materials. The scope of application of metal drills is limitless: the tool is used in the most different areas activities and in everyday life.

It is difficult for an ordinary buyer to navigate among the wide range of drills that are presented on the construction market today. Without competent consultation with a specialist, choose suitable model It's hard enough.

Structurally, a metal drill has a working part (cutting and calibrating part) and a shank.

Metal drills belong to the category of spiral drills, since they have spiral-shaped grooves along the entire length to remove chips

The place at the end of the drill is the cutting part, where the pointed edges are located to ensure the penetration of the drill into the material. Behind the cutting part there is a calibrating part equipped with grooves for removing metal chips. The calibrating part is responsible for the smoothness of the edges of the hole and sets the desired diameter.

The material of manufacture and the structure of the working part determine the purpose of the cutting tool.

The drill is attached to a hand tool or machine through a shank, which can be conical, cylindrical or hexagonal.

Classification of drills for metal

Depending on the design features, metal drills can be divided into the following types:

Features of marking drills for metal

When choosing a drill for metal, you need to pay attention to its markings, which may indicate the diameter, steel grade, accuracy class and manufacturer.

Drills with a diameter of up to 2 mm are not marked; on products up to 3 mm, the diameter and grade of steel are indicated, and on drills of large sizes, more extensive information may be indicated.

Basic designations:

• marking starting with a letter R indicates high-speed steel products;
• numerical values ​​determine the content of a particular substance in the alloy, for example: K6- six parts of cobalt (increases the heat resistance of products); M4- molybdenum content;
• for comparison, a drill with markings R6M5K5 much stronger than a drill with markings R6M 5, due to the addition of cobalt (the price of reinforced cobalt drills is higher than conventional ones);
• imported analogues have designations H.S.S. or Din; HSS metal drill usually has additional marking from Latin letters indicating the working material ( HSS-G drill alloy and carbon steels, aluminum and copper alloys, cast iron; HSS-E in addition to the materials listed, they will cope with acid-resistant and stainless steel; HSS-G Tin- especially durable, suitable for drilling titanium alloy).

For drill manufacturing for metal, GOST regulates the use of tool high-speed steel grade P18

What can the color of a drill tell you?

The method of final processing of the drill will play an important role in ensuring the strength and reliability of the tool. The color of the drill indicates what materials were used to process the product.

Grey colour indicates that the drill could not be processed in any way. This is the cheapest and least stable product, which will not cope with all types of metal and will not last long.

Black color the drill acquires after treatment with superheated steam - this increases the service life of the product.

Dull golden hue- a sign of using tempering to relieve internal stress in hardened metal. This procedure reduces the fragility of the hardened drill, giving the material strength.

Rich golden color have drills coated with titanium nitrite - this ensures the highest wear resistance. These drills are the most convenient to use (reduced friction) and durable, the only drawback is their high cost.

Proper sharpening of a drill: the need for the process and the algorithm of actions

A high-quality drill is designed for long-term use, however, it can become dull over time. Of course, you can replace it with a new one, or you can avoid unnecessary expenses and sharpen the drill yourself.

In everyday life, for economic needs, drills with a diameter of up to 16 mm are usually used, which can be sharpened on a regular sharpening wheel without resorting to “high technology”. If you don’t have a sharpener, you can use a grinder or electric drill, which must be secured before work.

Before you start sharpening a metal drill, you need to prepare:

• eyes must be protected with glasses, hands with gloves;
• prepare a small container for coolant (machine oil, water) - if the drill is not cooled periodically, the metal will overheat and will not be able to withstand high loads during drilling in the future.

The sequence of actions when sharpening a drill is as follows:

1. Pressing the drill tightly against the grinding wheel, we process the back surface of the tool. The sharpening angle should not change.
2. After finishing processing the back surface, a regular cone should form (you can see it by looking at the tip of the drill from the side).
3. While maintaining the sharpening angle, the working part of the drill is processed.
4. Finishing of the rear part of the tool occurs after processing the working part of the drill.
5. The size of the bridge at the tip of the drill should not be more than 0.4 mm (for drill diameters up to 8 mm) and no more than 1-1.5 mm for larger drills.

You should not concentrate only on the tip; the entire working surface must be sharpened. side surface drill

When sharpening for the first time, it is advisable to practice on old, worn-out drills in order to feel how to hold and press the tool correctly. If you insert a “test piece” into a drill and drill a couple of holes, it will immediately become clear where the error was made during processing.

When choosing drills for working with metal, you should adhere to the following recommendations:

With the right choice of tool and good sharpening, metal drills can be used for a long time and without problems, both for their intended purpose and for drilling holes in other materials: wood, plastic, plexiglass and stone.

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 no universal products that would be suitable for processing all types of metal products. 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 specific type metal

What types of drills are there, according to markings and appearance Find out in this article how to choose the right product for the job.

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 to correct defects from other cutting tools.

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

The advantage of using this type of drill over others is the production of holes large diameter. 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 heating of the working surface during operation. 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.

When used correctly, titanium models retain their factory sharpness 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 mechanical strength sample. By color you can determine the composition and quality of workmanship.

Grey

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

The quality of the tool, 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, which will need to be used in large quantities for complex work.

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 making deep holes, then purchasing models that are too long will lead to cost overruns Money.

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 poor 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.

Whatever set of drills you take, each one will contain only the highest quality products that will last for many years, provided they are properly stored and used.

2. "Bison" - 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. Soviet-made drills - 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.

For those who carry out construction and installation work, the drill will be the best assistant. When inserted into a drill or other power tools, it will drill a neat hole or tighten a screw.

There is no universal drill, and an incorrectly selected one will ruin the job or make it impossible, so you should carefully choose it. In most cases, you will have to select a drill yourself, because, unfortunately, not every seller in a hardware store will give the right recommendations on the quality of this tool and the work for which it is suitable.

Do I need to buy drill bits in sets? How do you know what shape a drill should be? What drills are suitable for? You will find answers to questions in the article.

1. Spiral – universal, suitable for any type of hole;
2. Conical - characterized by a smooth conical shape, suitable for holes of any diameter. Need constant supervision from a master;
3. Stepped – also conical in shape, but they make the process of drilling holes of a certain diameter easier due to the presence of steps of different sizes;
4. Core cutters (annular cutters) – for holes with a diameter of 12 to 150 mm, multi-layer materials. They are characterized by low cutting force and produce high roughness values ​​that cannot be achieved with other types of drills. Suitable even for conventional drills. The shank must be strong and powerful to prevent slipping in the chuck. They are chosen depending on what kind of work is being done and what type of steel is being used. They differ from wood drills by the sharpening angle and the presence of two longitudinal grooves that divert the chips to the side.

Options in the photo

The most powerful drills for large holes
Due to the steps of a given diameter, such drills make it easier to drill standard holes. Working with a conical drill requires constant attention from the master.
Twist drills are the most common and common

Professionals identify 5 points of general criteria for choosing a metal drill:

1. The type and characteristics of the metal you are going to work with, including the grade of steel;
2. Depth of “penetration”;
3. Type of drilling (through or penetrating);
4. Hole diameter;
5. What kind of tool do you use (hand or electric drill, varieties - hammer drill, screwdriver or drill), its general characteristics.

Please note that buying a set of drills for household use not worth it. If you don't use drills for professional purposes, you won't need many tools and your money will be wasted. If you are going to buy a drill for permanent use, do not skimp.

Features of choice

Professionals choose drills based on the following criteria:

1. Material;
2. Blossom;
3. Labeling;
4. Sharpening angle;
5. Size;
6. Shank;
7. To the manufacturer.

It’s not difficult to identify them by eye, but before doing this, be sure to find out what type of drill you have. For example, large cross-section holes will require low-speed, high-power drills with appropriate drill bits. Additionally, please note that some types of drills are used only with cooling solutions, in order to avoid burning them and the metal.

Which material is better

To use a drill at home, it is better to choose one drill for working with metal of different densities. When choosing a tool for working with aluminum and steel, focus on cost.

Cheap - products made in China. They quickly break or become dull. For long-term work, they will be required in the plural, and their total cost is disproportionate to the purchase of a single, but high-quality drill.

When looking for quality tools, turn to products from well-known brands. They are made of solid steel and are solid rolled.

Top quality drills - solid rolled

Counterfeits are determined by weight. The drill should not be too light.

Choose by color

On store shelves you can find drills in the following colors, which directly indicate their quality:

This does not mean that you don’t need to buy gray or black drills. Approach the choice from a practical standpoint - if you only need to drill a couple of holes, you can save money by buying several drills, and if you are planning more global work, it is better to buy a “golden” drill, which will last much longer.

Marking

All data about the drill is printed on its shank

The drill marking implies a certain combination of alphanumeric values ​​and indicates:

• Drill diameter;
• Steel hardness;
• Metal impurities in the alloy;
• Technology and place of production.

Please note that markings are not placed everywhere - for example, drills with a diameter of less than 2 mm do not have them. On domestically produced instruments with a diameter of 2 to 3 mm, a mark and section are given, on products with a size of 3 mm or more - data on the cross-section, grade of metal, impurities in the alloy, trademark. If you decide to buy imported drills, they will indicate the country of origin, brand of company and metal alloy, drill diameter and cross-section, accuracy class and recommendations for use.

The highest quality drills are characterized by the USSR marking.

Main types of marking:

• HSS-R and HSS-G – suitable for working with cast, alloyed, carbon steel with a strength of up to 900 N/mm2, aluminum, cupronickel, graphite, bronze or brass alloy and cast iron;
• HSS-G Co 5 – for processing metals with a strength of up to 1110 N/mm2, suitable for drilling stainless steel, carbon, alloy, non-heat-resistant, heat-resistant steel;
• HSS-GTiAN/TiN – drills with titanium-nitride-aluminum coating, suitable for working with cast iron, brass, cupronickel and bronze, cast steel.

There are also drills made of cobalt (one of the most expensive and durable types of drills, suitable for drilling hard metals) and hard metal alloys (suitable for metal processing large thickness, have a one-sided, acute sharpening angle).

Sharpening angle

The sharpening angle is the angle between the edges

The sharpening angle is the angle between the edges. It differs for different types of metal. For example:

• Drills for steel have a sharpening angle of 116-140 degrees;
• To work with bronze, brass and aluminum, you will need a sharpening of 110-135 degrees (such drills are most common);
• For stainless steel - 120 degrees;
• For cast iron - 118 degrees.

The ease of drilling depends on how correctly you select the drill according to the sharpening angle. different types metal

What size are drill bits?

There are different sizes of drills, but our country’s GOST sets the following parameters:

• Short (GOST 4010-77) – diameter 0.3-0.20 mm, length – 20-131 mm;
• Extended (GOST 10902-77) – diameter 0.3-0.20 mm, length – 19-205 mm;
• Long (GOST 886-77) – diameter 1-20 mm, length – 56-254 mm.

They allow you to make holes of different depths.

What is a shank and what are they?

The shank is the part of the drill that is clamped by the drill or hammer chuck. At first they were of the same type - tetrahedral, placed in the hole of the drill chuck and secured with a screw. Later, improved types of shanks appeared, used for various types of tools.

Shanks are:

1. Cylindrical - found most often. As a rule, such products have the same base size and drill diameter. Sometimes there are models in which the shank is thicker or thinner than the drill. The disadvantage is that the shank slips, which makes it impossible to transmit a large torque to the drill. Advantage - if the drill jams in the working surface, the drill will be protected from damage;
2. Hexagonal (aka hexagonal and hex) shanks - suitable for various types of drills. Disadvantage: insignificant accuracy when using a ¼-inch holder;

   This shank shape fits almost any drill model

3. SDS shanks are the brainchild of TM Bosh for hot changing drills in rotary hammers. There are different types: SDS (with two grooves with a diameter of 10 mm, inserted into a 40 mm chuck), SDS-plus (common shanks with a diameter of 10 mm, placed into a 40 mm chuck, used on light hammer drills, drill diameter - 4-26 mm ), SDS-top (rare, have 2 open and 2 closed grooves, characterized by a diameter of 14 mm, in a chuck - 70 mm, drill diameter - 16-25 mm, suitable for 4-kg class hammer drills with a replaceable chuck), SDS -max (widespread, suitable for drills over 20 mm, inserted into a 90 mm chuck, diameter 18 mm, have 3 closed and 2 open slots), SDS-quick (4-10 mm), SDS-hex (used in jackhammers, pikes, drills);

   Shanks designed specifically for rotary hammers

4. Splined shanks – have the same parameters as SDSMax;
5. Triangular - clamped into three-jaw chucks, the main advantage is that they transmit large torques;

   These shanks provide the greatest torque

6. Conical - used in industrial hand drills and machines.

The best manufacturers

When purchasing drills, it is important to pay attention to the manufacturer. In this case, the price justifies the quality, and the more famous the brand, the better the sharpening of the drill, the metal alloy, wear resistance and resistance to excessive heat. If you buy a non-disposable drill, do not skimp on the tool. For one-time work, cheap options are suitable.

For convenience, we have combined the characteristics of the main manufacturers into a table:

Trademark	Characteristics	Approximate cost (depending on the type, length of the drill and the number of pieces in the package)
USSR	Reliable brand with high quality metal.	from 15 to 10,000 rub.
Ruko	Good quality and reasonable price. The most popular is the TL 3000 line - drills with cross sharpening and titanium coating.	from 30 to 1,000 rub.
Bosch	The drills from this company are considered the best.	from 70 to 7,000 rub.
Haisser	Powerful drills used in industry and everyday life are characterized by a titanium alloy, a sharpening angle of 135 degrees, and mesh grinding.	from 150 to 5,000 rub.
Bison	Drills made in Russia. Advantages: reasonable price and quality. Professionals recommend the Cobalt series, which has good accuracy and compliance with GOST 10902-77.	from 35 to 700 rub.

You will find drills in stores different sizes and format, different in hardness and colors, divided by sharpening angle, with different shanks and with a variety of manufacturers. In order not to make a mistake when choosing a drill, decide what you need it for now and whether you will need it in the future. If you follow these principles, buying a drill won't be a problem.

Home craftsmen are often faced with the need to drill holes in metal products, and most of them are somehow familiar with this operation. The process of making holes is simple at first glance, but to obtain a high-quality result, the master should adhere to some rules. This article will provide information about what kind of metal drills there are, how to choose the right drilling tool before starting work, about the types of drills, and other useful facts that will help the master understand everything about drills.

Design features

Depending on the design features and its functionality, the entire drilling tool is divided into several characteristic types. So, according to their purpose, the following types of drills are distinguished:

• for drilling organic glass;
• concrete products;
• ceramic parts;
• wood;
• plastic components;
• gimlets for drilling in metal.

The design of the drill is the main distinguishing feature of the corresponding type of drill from its other “brothers”. The following main parts of the drill may differ:

• cutting part of the gimlet;
• shank;
• a working surface that also performs the function of removing chips from the drilled passage.

Classification of drills by type of design

When working with metal parts, we can distinguish 2 main groups of drilling devices:

1. Flat (or feather) drills - such a tool has replaceable plates to a core drill, it is undemanding to the accuracy of the angle of application of force during drilling work, it is structurally simple and has a low cost, but at the same time it easily loses the diameter of the working surface during sharpening and does not have a structural groove for removing chips.
2. Twist drills are cylindrical drills that have one or two grooves on the surface of their body to remove chips.

When working with metal, it is important to select a drilling device that matches the material. In order for the work to be done efficiently, the master must be able to distinguish metal drills from similar ones. The drill configuration for both materials has similar elements; in both cases, the tools can have a diameter of up to 80 mm and a length of up to 600 mm, the drilling technology is identical and, moreover, the drills have the same markings. But despite all the similarities, wood tools are not always suitable for metal drilling, and vice versa.

First hallmark is the hardness of the gimlet: for drilling holes in metal, a tool with a higher hardness is selected. You need to understand that the hardness of metal drills is not a constant parameter and, in turn, also depends on the strength characteristics of the material on which drilling work will be carried out.

The second difference is the type of sharpening of the cutting elements. The device for drilling wood has a sharp nose at the tip in the form of a pin or corner, which prevents the gimlet from sliding relative to its specified position. Such fixation is not required when working with metal. The angle between the cutting edges is also different and directly depends on the material for which the drill is intended.

When carrying out drilling work on wooden parts and the master decides to use a tool designed for metal work, you need to understand that distinctive characteristics, listed above, can play a key role in obtaining a quality hole with smooth edges and without scorching.

An important role in obtaining a high-quality hole is played by the factor of whether the drill manufacturing technology was followed correctly. If something was broken during the production of metal drilling tools, then no correct form The gimlet or its corresponding color will not be able to ensure a high-quality result of the work and the service life of the drilling product will be significantly reduced. Information on the dependence of the color of the drill on what metal drills are made of can be found in the chapters below.

Types of metal drills

Understanding the types of drills will help the master decide and make a choice in favor the best model drilling product.

Titanium drills have best performance its drilling characteristics. Subject to the rules of operation of such drills, titanium products will delight their owner with excellent work results for a very long time.

Determining the type of drill by the color of its surface

The color of a drilling tool is an important feature that allows us to draw appropriate conclusions about its quality and durability. Different types of gimlet colors have different strength characteristics, the choice of which should be based on the frequency of use of the tool, its accuracy and the requirements for the quality of the finished hole.

Gray drills are short-lived and the least reliable due to the complete absence of any protective coating, which makes them susceptible to changes in mechanical properties in the worst side under the influence of high temperature or force loads. Such drills have a low cost, but their use will be one-time.

Black metal drills, compared to gray ones, are of better quality. The manufacturing technology of black gimlets involves treatment with high-temperature steam, which increases their strength and resistance to wear. Drilling products with a black surface also have a low cost, which attracts the attention of many craftsmen.

Drills with a light yellow coating have a very good safety margin. Internal stresses in such products are eliminated by thermal tempering even at the stage of their manufacture, due to which high strength of the tool is created. For their manufacture, they resort to the use of high-quality high-speed tool steel. Despite all their advantages, pale gold drills are inferior in their characteristics to brighter specimens.

The bright yellow drill bits are made of high-strength steel coated with titanium nitride. Products with a similar color when making holes experience minimal frictional force, which has a positive effect on their service life. The cost of such gimlets is quite high, but they fully pay for themselves due to their long service life.

Explanation of drill markings

When choosing a suitable drilling device, the master will be guided by the appropriate markings of metal drills. The marking of drills contains information about its working diameter, steel grade and information about the manufacturer.

Thus, on drilling products with a diameter of up to 2 mm, markings are not applied due to the miniature nature of such products.

For drills with a diameter of 2 to 3 mm, information about the steel grade and working diameter will be located on the body of the gimlet.

Drills with a diameter of more than 3 mm will inform the craftsman about the data of their diameter, the letter designation of the steel grade from which the drill is made, and the logo of the manufacturer.

The alphanumeric designation of the steel grade contains the following information:

• alloy category;
• the presence of additional impurities;
• chemical composition.

Features of marking drills for metal of domestic production using a letter designation indicate the following:

• letter “P” - the tool is made of high-speed steel. The number after it indicates the percentage of tungsten in the steel;
• letter “M” - the alloy is alloyed with molybdenum, the percentage of which is also indicated by the corresponding number after the letter “M”;
• letter “K” - the alloy contains cobalt in the amount indicated by the number following the letter.

As an example, you should familiarize yourself with the following designations used for marking domestically produced drilling products:

• R6M5K5 - a gimlet made of high-speed steel containing 6% tungsten, 5% molybdenum and 5% cobalt;
• Drill SCP R6M5 is a spiral drill with a cylindrical shank, the alloy of which contains 6% tungsten and 5% molybdenum.

Foreign products have a distinctive HSS marking, which also contains information about the alloying element using additional symbols.

• HSS-E – the drill alloy is alloyed with cobalt, which will have a positive effect when making holes in metals with high viscosity;
• HSS-R is a carbide gimlet, which has increased strength and is used for drilling cast products, parts made of brass, cast iron, bronze, cupronickel and alloys, with a strength of up to 900 N/mm2;
• HSS-TiN (-TiАN) – the drill body is subjected to titanium coating, which increases the hardness of the working surface and reduces the change in mechanical properties under the influence of high temperatures, up to +600 ºС, which allows you to work with materials with a strength of up to 1100 N/mm2;
• HSS-E VAP – gimlet suitable for stainless steel;
• HSS-4241 is a drilling device for working with aluminum alloy.

Based on the characteristics offered by the main drill classification, you can find the best metal drills. When choosing, the master must take into account the technological tasks that will be solved with the help of a drilling product, as well as the material on which the work will be carried out. The right choice should be based on special attention to the following characteristics of gimlets:

1. Drill color.
2. The quality of sharpening elements and the symmetry of parts of the gimlet design.
3. Working diameter of the drill.
4. Functionality and intended purpose of the product.
5. The material from which the drill is made.
6. Match the type of drill to the equipment on which it will be used (for example, to drill a large diameter hole, a low-speed drill with a high power rating will be required).
7. Company manufacturer.

The choice of a high-quality drill directly depends on the integrity of the manufacturer, because no self-respecting company will allow low-quality products to go on sale. Drill manufacturers who have been offering their tools for a long time are the real guarantee of purchasing a high-quality gimlet. Professional drillers give their preference to the strongest drill bits and choose the following drilling tools:

• drills produced at enterprises of the former USSR;
• drills from German manufacturers Ruko, Bosch and Haisser;
• Russian drills from the Zubr company.

These are the most common companies offering high-quality tools for a long time, but the choice is always up to the master, because the market is replete with drilling tools for every taste and budget.

Choosing a drill for household use

To carry out frequent drilling work in a home workshop, the driller should consider purchasing a ready-made set with products different diameters. A similar set, depending on the quality characteristics, is presented on the supply market in different price ranges, so every master will find necessary tool in their own way financial capabilities. If the drills certain type will be used more often, it is additionally worth buying a set of spare gimlets with a certain diameter. The master’s knowledge of what types of drills there are, what types of tools are better and which ones are the most durable will help the driller make right choice metal drills in favor of the best tool.

It is worth remembering that any choice of drill will be justified if the master handles it skillfully and sharpens it in a timely manner. Careful use of the gimlet for its intended purpose will allow for significant savings in money without the need to constantly replace failed drilling products.