What are the best metal drills? How to choose, review of manufacturers. Choosing a metal drill, how to do it correctly, expert advice How to choose a durable metal drill

Nowadays, buying a high-quality metal drill is a real problem; most drills are Chinese, their quality leaves much to be desired. The quality of a drill depends, first of all, on the grade of steel from which the drill is made.

Most modern metal drills are made of R6M5 steel, although the difference between modern drills and drills from the USSR (with a quality mark) is simply huge, Chinese drills instantly roll up and it is impossible to drill even an ordinary corner made of 3mm iron with them. One drill is enough for several holes. However, there are also high-quality drills that last a long time.

Let's look at the grades of steel, because the quality and durability of the drill depends on this.

P18 is now a legendary steel. Containing 18 percent tungsten, this steel supports metal processing even at high speeds. Drills made of P18 steel do not overheat, endure for a long time and drill well. True, finding the real ones is a whole problem. In Soviet times, r18 steel was used very widely for the manufacture of metal-cutting tools, but after the 70s, tungsten reserves were depleted and it was replaced by steel with a lower tungsten content - r6m5.

R6M5 - 6 percent tungsten, 5 percent molybdenum. Standard steel for metal-cutting tools. If the drill for metal is a Soviet one made from R6M5, then it is perfect for everyday use at home; such drills last for a long time, although they cannot drill through more hardened iron. The following drills with the addition of cobalt are suitable for this.

R6M5K5 is the same as R6M5, only 5 percent cobalt is added, which makes these drills even stronger and more durable. Drills with cobalt are suitable for drilling where drilling results in high temperature. Photo:

Excellent for drilling stainless steel, as well as other hardened steels. In general, if ordinary drills do not take iron, then buy one with cobalt, you will feel the difference.

HSS - foreign analogue quickly cutting steel, translated as High Speed Steel, that is, steel for working at high speeds. HSS drills are similar in composition to the standard P6M5 high-speed cutter.

By the way, hss also comes with the addition of cobalt; drills are marked HSS-Co. Drills with this marking will be identical to our R6M5K5. Drills with cobalt - for drilling stainless steel and other durable steels.

It is also worth mentioning specialized ones, they are soldered and also come with crowns, if you are looking for information, follow the link, I prepared an article at the request of workers.

In general, if you decide to buy high-quality drills for your home, then I would recommend first asking around for drills from the times of the USSR, if they have a quality mark on them, then this is generally better than that. Soviet ones are inexpensive, you can even look at flea markets, you can probably find something there too.

Sovdepov drills are an excellent tool. If you take imported ones, then they cost a lot, for example, 6 mm HSS-Co drills cost around 70-80 rubles, while a similar Soviet one can be bought for 20-30 rubles.

Drills and drill bits are the most basic tools in household, and almost everyone has it, and those who don’t know where to get it. Sooner or later, everyone will have to use a drill. Or if with wood or even stone everything is more or less clear, and you can drill a hole, so to speak, by touch, by feeling, then with metal this will not work. This is a very stubborn material. Let's figure out which metal drills are better?

Drilling is an entire art that can be studied and improved: drilling angle, pressure, but most of all, experience and the tool decide.

The problem is that most drills are sold of poor quality, especially in markets. It is better to order via the Internet, or in specialized stores where you can see and touch the material.

What you need to know about metal drills

There are a huge variety of metal drills; in addition to the fact that you need to look at the quality, you also need to pay attention to the shape and color. The product is built from the following elements:

The main (cutting) part, which performs cutting (drilling) of metal;
Working surface. Its role is that when the main part is working, chips appear, which are removed by the working surface;

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Sergey Yurievich

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The end, also called the shank, is attached to the drill chuck, and movement begins from it.

Metal drills come in many different shapes, each of which is used for a specific type of work.

Depending on the form, there are the following types:

The most common type known to everyone is spiral. In essence, it is a cylinder-shaped rod, and on the sides there are one or two spiral grooves (it is because of them that the chips are removed). In turn, twist drills have their own subtypes:

increased accuracy, often chosen by craftsmen to make a hole perfectly, down to the millimeter;
classic ones, the same cylindrical ones that are common among both pros and ordinary users;
narrow application, its spiral groove turned to the left, not to the right. It is used in cases where something needs to be drilled out.

Conical step drill. Unlike a cylindrical one, it can make holes of different diameters. Used to create new or expand existing holes.

Flat drill. As the name suggests, the working surface of this type is flat. The main disadvantage: due to its flatness, the chips are not automatically removed; you have to remove them manually. In addition, you cannot make large holes with this drill. But despite the huge disadvantages, they are in demand because they are very cheap and insensitive to distortions during drilling.

Core drills have different shapes cylinders, but upper part It is devoid of a base and is covered on the sides with teeth, which are made of hard alloy or coated with diamond sputtering. Used to create holes of different diameters.

The following types differ in that they are created specifically for hard metal, while the previous ones are for metals with high density If they don't fit, they'll break.

Cobalt. Can be confused with spiral, since it also has a spiral shape, but unlike it does not have a cylindrical base. In addition, thanks to cobalt, this type has high strength. But they are also expensive, so not everyone can afford them; before purchasing, evaluate the difficulty of the work.
Carbide. They are caused by the presence of a carbide plate on the cutting part, due to which it can make holes in fairly dense metals.

These are the facts that can tell the shape and structure of the drill, but the color also matters:

Rarely found, but still existing bright gold drill bits. This color indicates the presence of the hardest metal on the planet – titanium – in the alloy. Which goes without saying about the quality of the part and its strength and value.
Light gold the color indicates that the product has undergone special thermal preparation. Not as durable and expensive as bright gold, but the price is quite high, not everyone can afford it.
Drill black processed with superheated steam, thereby increasing its strength. The golden mean of price and quality.
WITH gray or metallic color – the most common and low-quality drills

Decide for what task you need a drill (what material needs to be drilled, what diameter of the hole), you can rely on this. Now you definitely won't take it cobalt drill, which is to make a small hole in a thin sheet of iron or vice versa.

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Sergey Yurievich

Construction of houses, extensions, terraces and verandas.

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When choosing a product, look at the sharpening, its symmetry;

The manufacturer can also play a role; the drills can be identical, but from different companies, in which case choose a manufacturer that you know or have dealt with.
To determine the working diameter, look at the marking, since on products up to two millimeters it is not marked at all, from 2 to 3 mm only the company’s mark is placed, and on products from 3 mm both the manufacturer and the working diameter are marked, so you should pay attention to this.

The variety of drills for hardened metal is huge, so there is no point in choosing, looking on the forum for which one is better, it all depends only on two things: the task that needs to be completed and the size of your budget for the purchase.

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

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

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

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

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

Why do you need a step drill for metal?

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

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

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

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

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

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

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

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

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

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

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

Design and characteristics of a cone-step drill

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

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

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

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

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

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

The tool has a hexagonal shank, which ensures better fastening in the chuck.

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

To produce these instruments we use different types steel. The most optimal choice will become a drill marked HSS. It indicates that with its help it is possible to process metal at high speed and at the same time it will not deform even with strong heating.

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

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

Advantages of step drill

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

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

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

Why does an electrician need a step drill for metal?

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

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

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

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

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

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

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

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

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

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

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

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 the best models 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 that 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, which is why this type of drill 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 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:

To process such material, you should choose products that have cutting edge a plate of increased hardness is located. Such gimlets are the best for processing hard alloys.
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 very well. 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.

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 the mechanical strength of the sample. By color you can determine the composition and quality of workmanship.

Grey

Gray drills 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 most best drill and at the same time not to 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:

Short, 20-131 mm long. Tool diameters are in the range of 0.3-20 mm.
Elongated, length is 19-205 mm, and diameter is 0.3-20 mm.
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 proper 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, any one will contain only the 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 last option will save you a lot of money cash, 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.

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

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

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

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

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

2 Wood drills – a set for all needs

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

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

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

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

The same laws exist for all drilling products correct use– the larger the diameter, the lower the number of revolutions should be set on the drill; the harder the material, the fewer revolutions; the longer the drill, the less pressure should be applied to it.

3 Drill markings: deciphering the designations

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

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

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

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

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

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

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

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

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

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