The smallest drill bit for metal. Metal drills

- it is important to know not only professional builders, but also for those who often do metal work with their own hands.

Today, in any hardware store you can buy drills of various shapes and sizes, and it is important to choose from all this variety of equipment exactly what you really need.

In the article you will learn which drills are best to choose in this or that case, whether it is worth buying sets and which ones, or just one device, as well as other questions that will help you decide on choosing the right drill for metal.

Before buying a drill, be sure to decide for what purposes you will use it, otherwise choose correct option will be almost impossible.

You should choose a drill based on the type of drill you will use in your work, as well as the type of holes you will need to make.

For holes with large section, drills are used that have the appropriate length and diameter - usually these are powerful drills with low speeds.

Drill color – important criterion, helping to choose the right correct device. By color you can easily determine the quality of the product and, therefore, its expected service life.

It’s better not to buy a gray device, because... they are the least reliable of all.

The gray color indicates that the drill has not been processed in any way: such tools do not have a protective layer, resistance to fire or deformation.

Naturally, buying such a drill will be the cheapest, but you won’t be able to use it more than once.

A black metal drill differs more high quality, because it was processed using superheated steam.

The service life of such products will be higher, as well as the cost, but their price is low, so buying such drills will not be a problem.

The best drills are those that have a golden hue, but they also differ from each other.

Tools with pale gold are somewhat inferior in quality to bright products - they undergo a processing process that allows you to relieve the internal stress that is present in the material, and also increases the strength of the product.

The most expensive ones to buy are bright yellow drills, however, they are the strongest and most durable. They are made from titanium, the most durable type of metal.

Such drills have a minimal level of friction, so it is more convenient to work with them, and their service life is much longer compared to other tools.

Of course, it is logical to buy the highest quality device - this way you will save time and be able to use the tool much longer.

If metal work is not your full-time activity, then you can get by with cheaper analogues - black or light golden drills.

The most important factor when purchasing a drill is its size.

It’s easy to buy a drill of the size you need, because... The size range for this tool is very wide - the main thing is to know what size you need.

If you are not sure which size to choose, then it is best to follow the GOST classification, which divides all devices into 3 groups.

The first group includes short instruments, the size of which does not exceed 20 mm in diameter and 131 mm in length.

The elongated group includes tools that reach a length of up to 205 mm, while their cross-section parameters are similar to short drills.

Long group drills include tools with a diameter of 1-20 mm and a length of 56-242 mm.

Drill shape

A drill is a simple tool and consists of only three elements: the cutting part, the shank and the working surface, which is necessary so that the chips do not accumulate inside the hole, but are immediately brought out.

Although this is a standard tool for working with metal, many people also use it to work with wood, plexiglass, ceramics, plastic, concrete and other materials.

Thus, you can choose its shape, suitable not only for working on metal, but also for other surfaces.

According to their design, drills are divided into two groups: the tools of the first group are called flat, and the second are called spiral.

Decide which of the two types is most suitable for you before you buy a drill.

The advantages of flat tools are that they do not react to possible distortions during work, are cheaper than spiral ones and have a simpler design.

The disadvantages of such drills are their smaller diameter during sharpening and the lack of automatic chip removal.

One of the varieties of such drills is a conical tool for metal. This drill can be purchased separately or in a set, depending on your need.

The conical type tool is used to work with drilling machine, or a two-handed drill. If you need to make a hole with a large cross-section, then pay attention to this option.

A more popular type of drill is the twist drill. They are more often purchased due to their great application possibilities - they are suitable for creating almost any holes and working with different materials.

Such a drill has the shape of a cylinder, and on its “body” there are special recesses-grooves in the amount of one or two pieces.

Thanks to their presence, the chips do not linger during operation, but are immediately removed from the hole.

Spiral devices differ in the type of tail: it can be standard, crown, designed for threading, left-handed, high precision or stepped.

The standard cylindrical device has a diameter of up to 12 mm and can be used both in production and at home.

Private craftsmen most often buy this type of tool. A core drill is used to create large holes with a diameter of at least 30 mm.

The tip of the tool has a crown equipped with teeth. This device is best used for working on thin metal.

The carving tool allows you to create carvings required section. If you purchase a tool for these purposes, then you need to buy one that is 1 mm smaller than the cross-section of the future hole.

The stepped device is the most versatile because it allows you to make holes of different diameters.

The only limitation on working with it is that it can only be used to work on sheet metal thickness no more than 2 mm.

The diameter of the tool is quite large and can reach 30 mm.

Buying such a drill is usually more expensive than others, but the price depends on the size of the section, and for small sections it will be quite acceptable.

The left-handed device can only be used to unscrew hardware: a screw, bolt or self-tapping screw, so buying it will only be relevant for these purposes.

Tools with increased precision are the best of all. They are purchased in cases where the result must be as high as possible.

The price of such devices depends on the accuracy class to which they belong - this can be class A1 or B1.

Manufacturer and labeling

Before you buy a drill, look at where and by whom it was made.

It is better to buy only proven devices, because... if the production technology has been violated, then neither the color nor the correct shape of the product will help create a high-quality result.

From the right technology production depends on how well the tool will be sharpened, how durable it is and can last, resistance to corrosion and other external influences, etc.

It is best to look in advance on the Internet for reviews of a particular company and buy a drill that has the largest number of positive reviews.

The highest quality metal drills are marked USSR.

Finding them today is not so easy, however, if you buy such a tool, it will last a long time: many note the high quality, long service life and minimal abrasion of the device.

Ruko tools are also deservedly popular: they are of high quality and reasonable prices.

The most popular models are the TL 3000, due to the fact that they have wide functionality, as well as cross sharpening and several layers of titanium modifications.

Such drills are not always used for working on metal - they are most effective in processing materials that form large chips, such as wood.

Before choosing a device marking, keep in mind that the diameter may vary depending on the manufacturer.

If you see a drill without markings, it means its cross-section is less than 2 mm; on devices with a diameter of 2-3 mm, the steel grade and cross-section are indicated, and on drills with a larger diameter you can also find information about the cross-section, grade of material and the presence of additional substances in it, if they are.

The instrument marking includes a combination of letters and numbers.

It is better to remember them before buying a tool: the letter P denotes high-speed steel, the alphanumeric combination indicates the presence of additional impurities in the material: it could be, for example, K6 - this is how cobalt is designated, but there may be other impurities.

If you decide to buy tools Russian production, then there will be no other markings on them, but if these are foreign instruments, then they must also indicate: country of origin, trademark, grade of material, cross-section and diameter of the instrument, advice on use and accuracy class.

Foreign instruments have specific markings, usually a combination of letters such as HSS-R, HSS-G, etc.

Metal drills are two-pronged cutting devices that are used to create holes in different materials, including in metal structures. Manufactured from alloy steel and hard alloy. They have a wedge-shaped body, which is limited by the anterior and posterior surfaces. The operational parameters of this cutting tool depend on the quality of the manufacturing material, its heat treatment, and also necessarily on the sharpening angle of the cutting part. Exist different kinds metal drills, each of which performs its own separate function and is used for cutting a specific element.

Classification of drills for metal

There are, for example, twist drills, feather drills, centering drills, for deep annular drilling and with straight flutes. According to several classifications, cutting devices are classified according to different parameters. Let's look at the main ones.

The following types of drills exist:

1. Spiral - the front surface is the helical surface of the groove.
2. Centering - have a combined design, made for centering holes of 60 and 75 degrees with and without a safety cone.
3. Stepped - used for processing holes with a cylindrical countersink specifically for screws that have a cylindrical head, as well as for processing holes and simultaneously forming a chamfer for the next thread.
4. For deep drilling – two screw channels have an elongated screw design.

By type of material there are:

• Carbide alloys;
• High speed steel;
• Universal

In the direction of drilling consider:

• Left;
• Right

Shank types:

1. Cylindrical device (used for processing structural materials).
2. Conical, with Morse taper (used for machining holes without preliminary centering).

By accuracy class:

• Increased accuracy;
• Normal accuracy

Drilling methods, the type and shape of the working part of the cutting tool, the method of manufacturing the tool, as well as its coating also differ.

According to the manufacturing method, they are distinguished:

1. Solid (diameter up to 8 mm);
2. Welded (diameter greater than 8 mm);
3. With replaceable plates;
4. With replaceable heads

By coverage from:

• black oxide film;
• titanium nitride;
• hard alloy;
• low alloy steel;
• titanium carbonitride

There are also several types of drill sharpening:

1. Single-plane;
2. Two-plane;
3. Conical;
4. Cylindrical;
5. Screw

Features of using drills

The most common are spiral devices. They have a diameter from 0.1 to 80 mm. Their design involves the presence of a working part, a shank, which is used to secure the tool in the spindle of the machine, as well as a foot, which serves as the main stop when removing the structure from the spindle or chuck. The base is a cylindrical rod that has two spiral or helical grooves that serve to remove chips while drilling a hole.

photo: spiral drills for metal

Feather drills are used quite rarely; their device consists of a round rod, the end of which is equipped with a flat blade, which has two cutting edges located at an angle of 120 degrees.

Deep-drilling cutting tools are used for drilling blind and through holes in long structures, shafts and spindles. They have low productivity, drilling precise, straight and clean holes. These include gun, single-edged and double-edged with internal chip removal.

Gun blades are used for cutting small-diameter devices, single-edge and double-edge blades are used for cutting medium- and large-sized devices.

photo: gun drill for metal

Ring drilling devices are used for cutting structures with a diameter of over 100 mm. Special cutters and keys are inserted into their body.

Centering cutting tools are designed for processing center holes in various workpieces. They can be manufactured with or without the safety cone and have a combined shape.

photo: center drill for metal

Types of metal drills that have carbide plastics at the ends have greater durability and are also highly productive because they have a high cutting speed. Their body is made of alloy tool steel, the plates are soldered using brass solder to the cutting part of the structure.

Drills with a soldered shank are also manufactured for processing holes that have a small diameter. They have increased rigidity and durability.

Cutting tools with straight flutes are used for machining cast iron installations and materials that are characterized by increased brittleness.

Helical grooves, in turn, are used for processing viscous materials.

Stepped structures are used for processing sheet material, are distinguished by strength, microhardness, precision manufacturing and increased sharpness due to the manufacturing method using turning from whole metal.

Features of drill selection depending on the material of the workpiece

When choosing a cutting tool, you must pay attention to the material from which the workpiece is made. In order to choose the right device, be sure to take into account the hardness indicator.

Designs with plates made of hard alloy VK8 are used for drilling materials made of cast iron, and those made of plastic alloy T15K6 and VK3-M for hardened steels. Carbide structures - for cutting high-strength and heat-resistant steels, processing cast iron and titanium alloys.

In order to cut a hole in the required structure, structures made of high-speed steel R18 and R6M5 are used. They have high cutting speed. Tungsten steel P18 is intended for the manufacture of shaped and complex tools that must have high wear resistance. R6M5 is used for steel and cast iron at increased cutting conditions.

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

There are different types of 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. If we're talking about about 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 the working area.

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

• Cylindrical - have a 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 from a threaded hole or fastener, which 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 which you can make holes with a 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 is 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 high price, which is compensated by technical characteristics.

If we talk about carbide structures, they differ in that they place 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 inserts 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 a large hole in a metal product, 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 been subjected to additional treatments 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 in terms 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 performance characteristics products.

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 are highly durable and reliable, resistant to wear and have 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 - products of this brand have their own design features; special alloys are used for their 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. Please follow these recommendations:

• Check whether the sharpening device is working properly and prepare a container with coolant.
• When sharpening, press the tool tightly against the grinding wheel, starting 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.

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 (more than 3 mm), then all possible parameters are indicated on it. It is necessary to know the marking features in order to select drills of the required size, since not all devices are suitable for drilling certain holes.

Twist drill markings: meaning of letters

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

photo: marking of a twist drill for metal

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

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

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

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

The marking of the p6m5 drill may not be indicated in this type of device.

Marking of the feather cutting tool

Strength is indicated:

1. P18 is a satisfactory indicator, increased grindability, indicating a wide range of quenching temperatures.
2. P 9 – characterized by increased wear resistance, a narrower range of hardening temperature indicators, and increased ductility.
3. P6M5 – molybdenum is additionally added, increasing the tendency to decarbonization.
4. R12F3 – have reduced grindability, used for drilling in medium mode. Added 3% vanadium.
5. R6M5F3 – increased wear resistance, work 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. It indicates the possible diameter value.

Conclusion

Each device must indicate the steel grade (P and number), additional elements included in the composition (M, K, F and 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.

Metal drills are intended for drilling holes in alloyed and non-alloyed steel, its various alloys, cast iron, and other types of various metals, as well as in particularly hard plastics. In addition, drills are used for drilling ready-made holes and drilling or, in other words, for creating blind recesses in metal. To understand how to choose a drill for metal, it would be nice to have at least a basic understanding of their classification, materials of manufacture and design features different types this cutting tool.

Types of metal drills

Metal drills differ from each other in several ways: manufacturing method, shank shape, scope of application, and, of course, diameter. First, let's see what kind of metal drills there are according to their design features. Here are their main types:

• Spiral or screw. Such metal drills are distinguished by the fact that they have the same diameter along their entire length and are used to produce both through and blind holes. The drill consists of a cylindrical working part with a pair of screw cutting edges and grooves along which the chips escape.
• Stepped. Unlike the first type on our list, these drills are not cylindrical, but conical, so they can be used to drill holes of different diameters without changing the cutting tool. The main advantage of step drills is their versatility, however, they are designed to work mainly only with sheets of metal, since they cannot drill a hole in a metal workpiece thicker than 2 mm.
• Crowned. Designed for making large-diameter holes or when drilling several sheets of metal at the same time, the so-called multi-layer hole making. Such drills differ in the frequency of cutting edges and are made of high-speed steel.
• Countersink. Also made in the shape of a cone. These are metal drills that are intended for countersinking, that is, this type of mechanical cutting in which both cylindrical and conical holes are machined to increase their diameter.

It should be noted that these are only the main groups of drills, each of which has its own subtypes. So, before choosing a drill for metal, you should decide which shank, or in other words, the part of the drill that is fixed in the chuck, will suit you best. Based on this feature, metal drills are divided into three types: with a cylindrical shank, hexagonal and conical. The first of them is the most popular and widespread, suitable for almost all drilling tools. Tapered shank drills are mounted without a chuck at all on some types of drills or drilling machines.

In addition, according to the characteristic features of their manufacture, metal drills are:

• Whole. As is clear from the name, such metal drills are made from the same material. This type includes screw drills.
• Welded. They differ from the previous type in that they are made of two different varieties become. This manufacturing method is used for large diameter drills.
• Carbide. The tip of such metal drills is made of a carbide plate made of a special VK8 alloy and has a special one-sided sharpening angle. Such features allow the drill to cope with the strongest metals. Carbide body drills even allow you to change used inserts without replacing the drill itself.

As a rule, all the necessary information about metal drills is applied to the drill itself. By understanding the markings, you can easily choose metal drills that are best suited for a particular type of work. In addition, the marking of the drill will tell you what material it can handle.

What steel are metal drills made from?

The vast majority of metal cutting tools are made of high-speed steel, which may have various impurities, such as tungsten, cobalt, chromium, vanadium or molybdenum. The presence of one or another additional metal in the composition of high-speed steel can be understood from the markings of the drill. Thus, the letter M indicates the presence of molybdenum in the alloy, the letter F indicates that the alloy contains at least 3% vanadium, and if the letter P is present in the marking, then this is a sign that the alloy contains tungsten. It should be noted that chromium and carbon are not marked.

What is high speed steel? This is a type of steel that has ultra-high hardness, resistance to fracture and outstanding red-hardness. Thus, conventional carbon tool steels are not capable of providing high drilling or cutting speeds, but high-speed steels, thanks to alloying with the above-mentioned impurities, successfully cope with such extreme conditions.

In addition, not only the markings, but also their color can tell something about the materials from which drills are made. So, bright golden indicates that the drill is coated with titanium nitrite. Such drills have a long service life due to their increased wear resistance. And the black color of a drill, for example, indicates that it has been treated with steam, which also improves the quality of the cutting tool.

Sharpening a drill for metal

Not everyone can afford to buy new drills every time they become dull. Moreover, a high-quality metal drill, and not a cheap Chinese knockoff, is quite expensive. The good news is that with basic skills and a sharpening machine, you can sharpen a drill at home, thus avoiding unwanted financial expenses. Even if you don't have a sharpening machine at home, a regular drill and sharpening wheel will do for this purpose. When sharpening a drill, you need to keep in mind that not only the drill head should be processed, but also the entire side cutting edge.