Black metal drills. Choosing a drill for metal: product types, marking and color

Metal drills are usually installed in drilling machines and drills of different models and designs. Productivity, speed of the workflow, as well as the minimum amount of marriage at the exit are largely due to the quality of the drill. Whether your design is spiral, deep hole, annular, or grooved, it is important to pay attention to performance characteristics tool. The quality of the product is determined by the following parameters:

• material of manufacture;
• degree of strength;
• sharpening quality;
• coating characteristics.

Asking the question about what drill bits are better for metal, the master does not mean its design (here the choice of tool depends on the purpose of its use), but how long and productively he will be able to use it.

Attention to detail

When buying a drill, you need to pay attention to the marking and nomenclature. For example, in foreign-made products, these are HSS and DIN. You should also be aware that drills with a diameter of up to 2 mm are usually not marked. What else affects the performance of the product?

• Angle of sharpening of the cutting part. An overestimated clearance angle reduces the strength of the cutting part, impairs heat dissipation. The vertex angle defines functionality drills: can it process cast iron, copper, other alloys.
• If you decide buy a drill for metal look at its color. Darker products last longer due to the use of superheated steam during the manufacturing process. The golden tint tool features reduced friction due to the titanium nitride content.
• Deservedly in high demand drills made of high-speed steel with molybdenum or tungsten are used.
• The presence of an oxide coating allows you to effectively remove chips during the drilling process.

The addition of cobalt to the alloy also has a positive effect on the quality of the drill, increasing its heat resistance. Products with the above characteristics in a wide range are offered by the manufacturer "EKTO".

Types of drills: their features and benefits

The structural elements of the drill are directly related to its quality characteristics.

• Screw products are reliable, strong and durable. The taper shank versions are great for drilling large diameter holes.
• Slotted structures are indispensable in the process of multi-layer drilling and are suitable for installation in low-power tools. The secret of their durability is in the timely cooling of the metal being processed.
• The main advantage of step models is their versatility. They are usually used in the processing sheet steel up to 2 mm thick.
• Elongated products are suitable for processing workpieces with a large length - spindles, shafts.
• When drilling a threaded hole, a threaded drill is used. When choosing this tool, the thread pitch should be taken into account. If it is 6 mm, then you need a drill 1 mm smaller.

A quality tool will last a long time, but the need for sharpening is inevitable. Products with a diameter of up to 16 mm can be put in order on grinding wheel. It is necessary to sharpen not only the tip, but also the entire side cutting part.

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 steel grade from which it is made, the accuracy class, as well as the country of origin or the brand of manufacture. Drills with a diameter of less than 2 mm are not marked, products with a size of 2 to 3 mm have diameter and steel grade designations. If cutting tool large size (more than 3 mm), then all possible parameters are indicated on it. Marking features you need to know in order to choose drills required size, since not all devices are suitable for drilling certain holes.

Twist drill marking: the meaning of the 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, a number is indicated that indicates the amount of tungsten that the tool contains. An average is taken. More letters and numbers follow. The numbers that are indicated after the letter indicate the content of the alloying substance in the alloy, this is a percentage parameter indicating the mass fraction of substances. For example, if K6 is indicated, this indicates that the alloy contains six parts of cobalt, which contributes to an increase in heat resistance. If M4, then there are four parts of molybdenum. That is, after the letter P and the number, a special letter (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 a twist drill for metal

For example, the following marking R6M5F3 is indicated. This means that the drill is made of high speed steel with the addition of 6 parts of tungsten, 5 parts of molybdenum and 3 parts of vanadium.

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

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. This value indicates the accuracy class of the instrument. It can be A1 - increased accuracy or B1 - normal accuracy. 2300 - operational and design characteristics, 7066 - serial number manufacturing. GOST - in accordance with what standards the device is manufactured.

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

An installation with a tapered shank has an indicator of 2301, for integral ones, the manufacturer's trademark, diameter, grade of hard alloy, 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 (metal addition P4M3 - molybdenum);
• HSS-R (metal addition P2M1 - molybdenum).

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

Designation of a center drill

The designation of centering drills is set in accordance with GOST 14952-75. They have an additional letter A, B, C or R in the designation.

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

photo: marking a center drill for metal

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

For example, if the number 0001 is indicated, then the diameter is 1 mm. Group B devices have marking features. 2317-00-12 if it's the second version, and 2317-0113 if it's the first.

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

Marking drill r6m5 in this type device may not be listed.

Marking of the first cutting tool

Strength is indicated:

1. P18 - a satisfactory indicator, increased grindability, indicates a wide range of hardening temperatures.
2. R 9 - are distinguished by increased wear resistance, a narrower range of hardening temperature indicators, increased ductility.
3. Р6М5 - molybdenum is additionally added, increased tendency to decarburization.
4. R12F3 - have reduced grindability, are used for drilling in medium mode. Added 3% vanadium.
5. R6M5F3 - increased wear resistance, work at an average cutting speed, used for carbon and alloyed tool steels.
6. Р9К5, Р6М5К5, Р18К5Ф2 - cobalt is added, which provides an increase in secondary hardness, heat resistance, and an increased cutting mode.

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 value of the diameter.

Conclusion

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

Today, any hardware store has a wide selection of metal drills. Among the variety presented, it is important to choose exactly what you need. How to choose drills, whether you need to purchase sets, and much more that can help right choice read this article.

The drills with which I process metal consist of the following elements:

• Cutting part (main work).
• Shank (with the help of it there is a fixation in the cartridge).
• Working surface (responsible for removing chips from the treated area).

To select the best and most suitable model, you should understand the types and shapes of drills. There are the following types:

• Spiral. Drills of a cylindrical classical form, which are most often used for drilling metal. it cutting type high quality steel. Differs in durability and durability.
  1. Cylindrical general purpose. The diameter can be up to 80 mm. They are used both in production and at home.
  2. Left hand spiral. Have limited area applications. For example, they are needed when you need to drill a bolt with a broken head or fastener which cannot be unscrewed.
  3. Drills of the increased accuracy. They are bought by those who want to achieve excellent result processing. They are labeled A1.
• Stepped (conical). The cutting surface has a cone shape. Used to make holes in thin metal - to eliminate defects in other cutting tools. At high density metal should choose products with a golden color. The use of this type of tool in everyday life is rare.
• Ring (crown). This is a cylinder with a cutting edge. The energy that is spent on making a hole with such a drill is low due to the small area of ​​​​contact of the tool with the working surface. It is possible to drill large diameter holes with better edges than spiral models.
• Feather (flat). They are a special kind of gimlets with interchangeable edges. With the help of them, they perform high-quality, even holes. There is no distortion during the drilling process. It is also possible to change the diameter of the hole.
• Cobalt. They are created on the basis of high-speed steel, which is alloyed with cobalt. It gives the product resistance to deformation (during mechanical or thermal action) and high strength. Used for drilling tough, high-strength alloys and metals.
• Carbide. The plates of the same name are located on the cutting part of the drill. Tool steel makes up the main body of the tool. In the production of plates, carbide alloys are used, which are distinguished by high wear resistance and hardness. Needed for drilling especially hard alloys and metals, as well as products of great thickness.

Shank design

The shank is the part of the product that is clamped in the binding tool. They are divided into the following types:

• Cylindrical. They are common, have the same diameter and base size.
• Hexagonal. Designed for different models of drills.
• Trihedral. For clamping in special chucks.
• Conical. Needed for hand drills.
• SDS and slotted. Designed for perforators the lineup diverse.



Drill manufacturing method

The drill can be made from a single piece of metal or alloy.

For the manufacture of the drill, soldering is used, during which the plates and tool holders are connected. For soldering, a special welding powder is used.

To reduce the consumption of expensive tool steel, improve product quality and reduce labor intensity in manufacturing, pressure treatment methods are used. After their application, a product with a shape and size is obtained. high precision, which allows not to do further mechanical processing.

What shape the hole needs to be machined

The difference and purpose of drills is what task needs to be performed. According to the shape of the hole, they are divided into the following types:

• square;
• conical;
• stepped;
• cylindrical.



What are the drills covered with?

There are the following coverages:

• oxide film. It has a black color, protects the tool from rust, overheating. Extends drill life.
• Titanium nitride ceramic coating. Very durable, extends tool life by 3 times. Such a product cannot be sharpened.
• Coated with titanium-aluminum nitride. More reliable than the previous one.
• Coated with titanium carbonitride.
• Diamond coating. He has no equal in strength.

Before you buy a drill for metal, you should familiarize yourself with the characteristics and design features each type, and adhere to the following recommendations:

• Purchase a tool made of high speed steel, which contains tungsten and molybdenum. The presence of these elements can be found on the label.
• Select the sharpening angle according to the type of material. For bronze, values ​​\u200b\u200bof 130 ° -140 ° are suitable, for cast iron products - 118 °, structural steel - 116 °, stainless steel - 120 °.
• Purchase products depending on the device in which they will be attached. Since fixation is carried out using a shank, close attention is paid to it.

Reference! If you do not want to understand the types and markings of products, you should contact a specialized store.

The main criteria for choosing: the desired diameter, the symmetry of sharpening, the strength and hardness of the product, the type of metal, manufacturer, price.

What does the color of the surface of the drill say?

The color that the surface of the drill has for metal is a parameter by which you can judge the quality of the tool:

• Grey. Low quality, low cost. Additional processing is not needed.
• Black. Treated with superheated steam for increased strength and wear resistance.
• Light golden. Heat treatment, which eliminated residual stress inside the tool, improved strength.
• Bright golden. Best drills for metal, titanium is present in the composition. Reduced friction force. High price.

Size classification

A diverse dimensional grid suggests standards by which a drill can be classified into one category or another. These standards include GOST 886-77, GOST 10902-77, GOST 4010-77. These documents form 3 groups for the diameter and length of drills that are needed when working with metal:

• Short. Drills 20-131 mm long, 0.3-20 mm in diameter.
• Elongated. Length from 131 to 205 mm, diameter corresponds to the first group.
• Long. Diameter - from 1 to 20 mm, length from 205 to 254 mm.

If you need to make a hole for a self-tapping screw, it is unreasonable to take a drill with a diameter similar to a self-tapping screw. To select a suitable model, you can use the tables that can be found on the Internet (dimensions of a sharp self-tapping screw with a press washer, for sharp self-tapping screws - black).

How to understand labeling

The designation contains the following letters:

• A - used for 60° openings, there is a safety cone;
• B - for 60° with fuse;
• C - for 75°;
• R - to get the shape of the arc.

There are also symbols that mean:

• P9 - increased wear resistance and ductility, however, the product has low thermal tolerance.
• P18 - high grindability for a wide range of hardening temperatures.
• P6M5 - addition of molybdenum, drills have a tendency to lose carbon.
• R12F3 - added 3% vanadium, the product has low grindability, designed for medium-duty work.
• R6M5F3 - have long term operation.
• R6M5K5, R9K5, R18K5F2 - contain cobalt in the composition, which guarantees hardness, heat resistance, as well as operation at high conditions.

Popular brands of tools from foreign manufacturers

For the accuracy of choosing drills from a foreign manufacturer, you should have an idea of ​​​​the material that will need to be processed with their help. So, manufacturers recommend the following when choosing a tool with markings:

HSS-R and HSS-G. Tools (strength up to 1100 N / mm²) with this marking can drill products:

• steel, made by simple casting and injection molding;
• from alloyed and carbon steels;
• from metal alloys, which include graphite, copper, zinc, aluminum, nickel;
• malleable and gray cast iron;



HSS-G Co 5 (strength up to 1100 N/mm²). These became:

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



HSS-G TiAN/TiN. If drills for metal have such a designation, this means that their working part is coated with a titanium-aluminum-nitride coating. It increases the resistance of drills to corrosion, wear, which affects the service life. This marking allows the use of products for metal processing with a strength of 1100 N/m². Manufacturers give recommendations on the use of such drills for processing:

• gray and malleable cast iron, which contains graphite;
• copper-based alloys (bronze, brass, cupronickel);
• steel billets, which were obtained by casting.



As for popular brands, preference should be given to products from the following manufacturers:

• Ruko. The drills that this brand produces are made with cross sharpening and have different type spraying. They have good value for money.
• Bosch. The name of this company speaks for itself.
• haisser. Products of this trademark successfully cope with the tasks set under extreme loads due to the design features and the use of special alloys.

AT modern world there is a large number of metal products. For making a hole in metal, nothing can do better than a special drill. For this reason, it is so important to choose a product. When using low-quality products, you can harm the metal object and yourself.

Metalworking does not cause difficulties only for those who know how and with what to work. Beginners in this business have to start with the basics, for example, to find out which metal drills are best or what shape of the tip is needed for round holes.

There are not so many special tools that work without the help of a machine. Therefore, it is important to understand what drills are, how they are classified and what they are intended for.

Drills for metal: design differences and marking

The modern market offers big choice cutting tool for metal processing. Can be purchased ready universal kit or a set of drill bits for metal.

For a one-time use, you should not pay for everything at once, but choose something specific to perform any operation that meets certain characteristics.

Tip: Considering the tool, pay attention to the markings, where many parameters are encoded. These are letters and numbers that all types of metal drills have.

By short inscription experienced master immediately understands all the parameters:

• metal of manufacture;
• what material to work on;
• working diameter of the drill;
• accuracy class;
• country of origin (logo).

Spiral gimlets of minimum diameter are not marked. But the rest of the designations will not be able to understand the beginner House master. For example, the R6M5K5 marking indicates a composition with a certain percentage of tungsten, molybdenum and cobalt - this is the highest quality drill.

But also with 15% cobalt too quality tool, in the designation P9K15 shows that this is a high-speed steel drill.

Imported products with alloy steel are marked with HSS:

• HSS-E VAP (for working with stainless steel);
• HSS-E with the addition of cobalt (for working on metal with increased viscosity);
• HSS-Tin with titanium (for increased hardness of the cutter);
• HSS-4241 drills aluminum products;
• HSS-R tool for maximum strength.

Attention: Look for the markings on the metal drill shank as shown in the photo.

What brand of drill is best?

In the stocks of home craftsmen, tools and equipment from Soviet times have been preserved to this day. It cannot be said that these were bad drills, especially victorious ones, but how to sharpen a drill for metal without equipment?

It is easier to buy a new cutting tool from foreign and domestic manufacturers:

• Bosch - any product of exceptional quality.
• Ruko - Look for the best hard facing cross drills for reliability.
• Haisser - their titanium nitride coated drills withstand extreme loads (processing steel, copper, bronze, cermets, etc.).
• “Zubr is a well-established domestic brand, the best value for money, offers reliable cutters for metal, in particular with cobalt.

Important: A hole in a thin product made of a pliable alloy will take any drill. For "specialists" working on metal, it is not profitable to buy cheap gimlets of dubious quality and spend time sharpening them.

As a rule, drills are specialized in metal and wood, but they can also work in other materials, including concrete, ceramics and polymers.

Drills, their varieties and characteristics

For metalworking, drills are used that structurally have much in common:

• cutter;
• working surface (provides advancement with chip removal);
• shank (fixed in the chuck).

Main classification:

• stepped or cone (conical) drills;
• feather (flat);
• crowned;
• spiral.

You can find other types of drills for metal in the catalogs, but these are only discrepancies in the names. For example, annular cutters are the same core drills. On the end part you can see the teeth with diamond coating. Standard core drills select the contour of the hole.

Step or conical drills - for holes of the desired diameter in thin metal plates. The advantage is that there are several diameters in one tip at once, but they are practically not used in everyday life.

Material classification

The cutting tool is most often produced from steel, but when metalworking with hard alloys, the temperature rises. If the temperature threshold is violated, the drill becomes dull - cutters with plates of sufficient hardness, for example, alloyed with cobalt, are needed.

Titanium drills are a good alternative to cobalt drills in terms of hardness and reliability. Technological use guarantees long-term work with factory sharpening.

Carbide Carbide Tool Demonstrates increased wear resistance. Although these drills do not require regrinding, this professional tool is used in thick metal. For these purposes, powerful drills operating at low speeds are used - the drills are included.

From intensive use, the tool loses its properties, but this does not apply to drills of a bright golden hue.

By the way, by the color of the drill, you can judge its performance:

• Black surfaces - from hot steam to increase wear resistance to extend the life of the application.
• Gray - drills for domestic use, after working with solid metal they are falling into disrepair.
• Golden - high-speed drills that have undergone a special hardening procedure, they inspire confidence even in experienced craftsmen.
• Bright golden surfaces are the best titanium tools for metalworking, but they are quite expensive.

The size of the drill bits for metal does not affect the quality, but a wide range of gimlets makes it possible to choose the right tool for any metal work. The size scale is regulated by GOST standards. The working length of the incisors ranges from 20 mm to 131 mm, in diameter their parameters are 0.3 mm - 20 mm.

Photo drills for metal

A universal and important tool, without which no repair can do, regardless of the complexity of the work performed, is a drill. Today, the building materials market offers a wide selection various kinds drills All drills differ not only in length, diameter, but also in the material they are intended for drilling (wood, metal, concrete, ceramic tile, brick, glass). Before drilling a particular material, it is necessary to select the appropriate drill size. Its type is selected depending on the work performed.

Drill for metal

Versatility is a hallmark of a drill for metal. This tool is indispensable when working with metals of various strengths. With it, it is easy to drill a hole in cast iron, non-ferrous metal, cermet, alloyed and non-alloyed steels.

Twist drills for metal today enjoy unprecedented popularity. This is the rod cylindrical shape, in which two helical grooves forming cutting edges are made. With respect to the axis of the rod, the grooves are located at an angle of 10-45°.

When buying, experts recommend paying attention to the material from which the metal drill is made. The most high-performance and high-quality cutting tool is made of alloyed and high-speed steel. As alloy steel, you can take the 9XC steel grade, high-speed steel grade P6M5. Tools made from such steels allow you to get a high rate in the drilling process, while being high-strength, durable and reliable.

Marking and color of drills for metal

Probably, each of us thought about what drills are made of, what does the marking stamped on the tool mean? How does drilling of one's own kind occur with the help of metal? This is because the product is made from high-quality and high-strength steel, and not from raw materials that penetrate the market from dishonest manufacturers.

What does drill mark mean?

What does the marking on the drill mean? Drill marking for metal has alphanumeric designation: the letter of the main element comes first, followed by a number indicating its percentage in the material from which the drill is made. The first two characters may also be followed by other elements. The letter P means tungsten, K - cobalt, F - vanadium, M - molybdenum. Chromium is usually not indicated in the marking, since it is always present in the source material (about 4%). Also carbon is not indicated.
For example, the marking of the R7M6K6 drill indicates that it is made of high-speed steel with a mass fraction of tungsten content of 7%, molybdenum - 6%, cobalt - 6%.

Domestic manufacturers do not put any information on metal drills with a diameter of less than 2 mm. A tool with a diameter of 2-3 mm is applied with a diameter and a steel grade. For all other drills, in addition to the above information, a trademark is stamped, and in rare cases, the accuracy class of the drill.

If threaded holes are drilled in the metal, a drill of a certain diameter is selected for each. For threads M4, M5, M6, M8, M10, M12, the diameter of the drills is 3.3, respectively; 4.2; 5.0; 6.7; 8.4; 10.2 mm. Large holes in the metal must be made in several stages, that is, at first a thin drill should be used, then the diameter should be increased to the right sizes. For example, in order to drill a hole with a diameter of 10 mm, it is better to drill it in two steps with 5 and 10 mm drills.

What does the color of the drill mean?

All drills are available in bright gold, black gold, gray and black.

The bright gold color indicates that titanium nitride was used in the processing of the tool. The titanium nitride-coated drill has increased strength. During the drilling process, less friction is created between the surfaces.

The black golden hue indicates that tempering was used in the raw materials in order to relieve internal stress.

Grey colour says that it was not carried out final processing to protect and strengthen the material. This means that the product is of poor quality - it will not last long.

Black color means that the tool has been processed with superheated steam, which has increased its wear resistance.

Cobalt drills for P9 metal from the Polmart trademark

For drilling high-strength metals, drills made of high-speed steel P9 DIN 338 are designed. These drills can work with both stationary and hand-held drills. The red hardness of the described drill for metal increases due to high content as part of the tool cobalt and other alloying elements. These cobalt drills are widely used for making holes in stainless, acid-resistant, refractory and high-alloy steels, the density of which reaches 1000 N/mm.

Drills for metal from the brand Bosch

Metal drill bits from Bosch of the HSS-CO product line are manufactured according to all standards from high speed steel. Thanks to these drills, chips are removed very quickly during the drilling process due to the oxide coating of the drill for metal. The drill has a sharpening angle in the form of a chisel and is equal to 135 ° with mesh grinding, it is used for drilling almost all steels.

The thermal stability is improved by alloying the drill with cobalt, while the tensile strength index is 1000 N/mm. This means that such a drill can be used for drilling almost all alloys, steels and at the same time perform production tasks of varying complexity. The required exposure of the outer diameter of the drill is provided by the h8 accuracy class.

Haisser Titanium Coated Metal Drills

These drills are sharpened crosswise and are one of the most powerful tools used in drilling in everyday life and industry under the most high loads. Titanium coated metal drills can work in tough conditions while providing maximum cooling of the titanium coating. Basically, such drills are used in industry and during complex technological works. The drill has a grinding angle with grid grinding equal to 135°. High wear resistance and practicality help to increase the service life.

Such drills for metal with titanium coating are used for alloyed and non-alloyed steels, non-ferrous metals, plexiglass, cermets.