What are the circles for emery - another educational program. Abrasive grinding wheels: classification, marking, selection Abrasive wheels for internal grinding of metal

2017-07-06

The types of abrasive wheels are distinguished by design differences and are regulated by GOST R 52781-2007 "Grinding wheel". The document defines the following types of products:

  • ring;
  • disc-shaped;
  • conical;
  • conical double-sided;
  • with undercuts on one or two sides;
  • with a recessed central part;
  • with cylindrical and conical grooves;
  • with two undercuts.

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Products of certain subspecies are used for different procedures: processing, grinding, tool sharpening. Wherein main criterion choice is associated with the type of workpiece to be grinded and the nature of the impact on its surface.

Grinding wheels with straight and annular profiles are used in domestic conditions and on compact machines for processing metal products, tool sharpening, edge cutting. They are also suitable for working with glass, stone, porcelain, ceramics.



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The most demanded circles are conical type (double-sided and ordinary). With their help, planes are processed and grooves of various shapes are made.



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Cup-shaped and disc-shaped diamond-coated wheels are widely used. In addition to diamond abrasive, other materials are actively used for the manufacture of wheels: electrocorundum, silicon carbide, elbor, bakelite. We will tell you more about the choice of attachments for the cutting tool below.

Application of abrasive wheels

The main field of application of abrasive wheels is cleaning surfaces made of carbon steel, cast iron, plastic, non-ferrous metals, glass, iron. Also, the tool is used for cutting bricks, tiles, slate, drywall, concrete. Products are actively used for cutting grooves and slots different forms and depth.

The circles that are installed on the drill deserve special attention. Such nozzles are used when carrying out repair and finishing works for cleaning walls before laying tiles and applying plaster. Removing paint stains, rust and other coatings is another area of ​​use for abrasives.

How to choose an abrasive wheel

To choose an abrasive wheel, pay attention to its markings. The scope of application of the products is of paramount importance. There are nozzles for industrial installations and hand tools... To work in a domestic environment, you need the second option. We will consider the rest of the points related to the choice separately.

Abrasive grit

The particle size on the canvas ranges from 12-4000 microns. It is indicated on the circle in the form of a special marking. The generally accepted encryption system is FEPA. The graininess index in the table is indicated by the index F. The lower the numerical value, the larger the particle size.

There are three main grit sizes:

  • large (F16-24);
  • medium (F30-60);
  • small (F70-220).

Large abrasive particles allow cutting metal, concrete and other hard elements with maximum speed. However, a fine-grained nozzle is required to carefully cut edges and grooves.

Circle diameter

The diameter of the circle must match the size of the cutting tool. There are products with a diameter of 80-500 mm on sale. Household machines are produced under circles with diameters of 115, 125, 150, 180 and 230 mm. The larger the size of the product, the easier it is to cut a thick metal part.



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Type of processed material

The best abrasive wheels are those that are suitable for the material being cut. Information about this will be given by drawings on the surface in the form of stone, concrete, ceramics, metal, etc. There are also universal products that are suitable for working with different coatings.

Rotational speed

Pay attention to the calculated rotational speed of the nozzle. It should be slightly higher than the one on which the grinder is running. This parameter is indicated by the color of the strip on the product:

  • green - 100 m / s;
  • red - 80 m / s;
  • yellow - 63 m / s.

Density of the circle

The choice of an abrasive wheel is influenced by its structure (density). This parameter shows at what distance the grains are from each other. The specific type of backfill is selected according to the density of the material being processed. There are three structure options in total:

  • closed - for metals and aggressive grinding;
  • half-open - for non-ferrous metals, paintwork materials, plastic;
  • open - for wood processing.

Here are some specific examples. Circle PS18EK with open filling is suitable for woodworking, removing rust, paint, putty. The PS22K semi-open accessory is designed for sanding metal and hardwood. The densely packed PS21FK is suitable for machining stainless steel.

Abrasive wheel marking

The complete markings applied to abrasive wheels include the following information:

  • circle type;
  • overall dimensions (height and diameter);
  • abrasive material;
  • grain class;
  • level of hardness;
  • material structure;
  • type of connecting element;
  • rotational speed;
  • accuracy class.

Circles are 125-150 mm closer to universal wheels. They weigh little, while easily solving diverse household tasks. Also, when buying, check that the diameter of the bore of the circle coincides with the mount on the grinder. The standard value here is 22 and 32 mm. Holes of 10 mm are available for circles that are installed on a drill.



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The marking of the circles is applied according to different editions of GOSTs, therefore there are differences in the codes in hardness, density and other parameters. Review the table below to understand the markers.




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  1. Abrasive material: 25A - white fused alumina.
  2. Granularity: 60, i.e. 800-630 microns.
  3. Hardness: K - medium.
  4. Structure: 6 - medium.
  5. Bonding element: V - ceramics.
  6. Imbalance class: 2.



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  1. Abrasive material: 14A - normal fused alumina.
  2. Granularity: 36-30, that is, 525-625 microns.
  3. Hardness: Q-U - medium / hard.
  4. Binding element: BF - bakelite with a seal.
  5. Imbalance class: 1.

How to calculate the need for abrasive wheels

It remains to figure out how to calculate the need for abrasive wheels when processing selected materials to determine the volume of purchases. There is no absolute calculation criterion, since the consumption depends on a number of parameters, including the quality, density and hardness of the wheels, as well as their compliance with the selected material.

The data in the following table will help in the calculations.



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In a simplified form, the flow rate can be determined in practice. To do this, you should:

  1. process a certain amount of surface;
  2. divide the footage by the number of nozzles consumed.

In a domestic environment, this calculation is sufficient. If we are talking about controlling production costs, the data is recorded and a document is drawn up on the rate of consumption of abrasives, which is signed by the director of the enterprise.

In most cases, to give the final product a smooth surface, metal workpieces are processed using special grinding wheels. Thanks to polishing, it is possible to achieve the external attractiveness of the element, as well as to supply it with the technical characteristics necessary in a particular situation.

This tool is widely used both when processing interior items and for fitting, for example, bar and panel parts. industrial production. Smoothing moving parts is especially important, since ensuring that their friction is minimized plays an important role in the operation of all equipment.

A fairly wide range of materials can be polished. These include stone, metal, plastic, and even wood. Removable nozzles allow you to form various grooves and recesses in non-ferrous metals, concrete walls, soft alloys, which are brought to the final version by cutting heads.

Often, grinding wheels are used not only for smoothing metal surfaces, but also for removing rusty deposits from parts, which is almost impossible to do without this equipment. In many cases, craftsmen acquire abrasive wheels for grinding machines, with the help of which other cutting tools are quickly used.

These products have gained particular popularity among jewelers, who are mainly engaged in the polishing of precious metals. The tool is also often used for processing the surfaces of semi-precious stones and ornamental minerals.

On the market you can find special types of grinding attachments that are installed on a drill. They are used in the process of conducting renovation works, for example, when cleaning walls for subsequent tiling. Certain types of wheels allow, when installed on an electric sharpener, to clean pipes from corrosion, remove old paint with plumbing and stuff.

Equipment types

To carry out the correct processing of parts, it is necessary to determine the type of grinding. Thanks to this, you can choose the best option for the abrasive attachment.

To the main selection criteria for this equipment include the following components:

  • the material from which the workpiece is made;
  • the nature of the work performed on the surface of the product.

Grinding wheels, equipped with an annular or straight profile, are often used for working on small emery and machine tools, in everyday life, as well as for sharpening by the end surface of the tool. Stone, porcelain and glass are topical materials used with this equipment.

The most popular are ordinary and double-sided bevel circles, the work of which is based on the surface treatment of the part with a plane. They also allow excavation in a wide range of materials.

Often experienced craftsmen have in their arsenal cup circles and tools with disc-shaped all-metal nozzles equipped with diamond dusting. The cup modification resembles the equipment of a straight profile with a tapered recess. It differs only in the rectangular arrangement of the end in relation to the lateral plane.

If we consider the types of equipment depending on the type of abrasive, a fairly wide range of tools can be distinguished. In addition to the aforementioned diamond spraying, which is usually used for sharpening and finishing carbide elements, electrocorundum is considered quite popular, which makes it possible to make one-piece nozzles. Corundum wheels are usually made without a pressed-in core and base.

An abrasive called elbor is especially strong. This material is based on cubic boron nitride, which is practically not inferior in its performance characteristics to diamond. Moreover, it possesses undeniable advantage, namely: a high level of heat resistance.

The technique of performing diamond spraying on abrasive nozzles does not imply the use of any binding elements, since it is applied to the metal in a thin layer. This is the reason for the significant high cost of such equipment. Abrasive wheels with lower strength are made using a binder ceramic composition, which usually includes materials of inorganic origin, such as clay, quartz, etc. They are carefully ground and added to the selected abrasive during the formation of the wheel. This makes the final product rigid.

There are two main types of attachments depending on the binder in the abrasive:

  • bakelite;
  • volcanic.

The most popular are bakelite nozzles, which include artificial resin, which gives the wheel the necessary elasticity and elasticity. However, the indicated component also causes a decrease in wear resistance, which occurs due to insufficient grain bonding. This is not the case with hard ceramic wheels. However, it is worth remembering that rigid bases with high hardness can provoke overheating of the metal being ground, and this is fraught with burnout of the surface of the workpiece. There is no such disadvantage in bakelite nozzles. They are quite soft, do not heat up the metal much and self-sharpen when working.

Wheels with a volcanic component are even more soft. They use heat-treated synthetic rubber as an abrasive element. In the process of manufacturing the equipment, a vulcanization method is used, which formed the basis for the name of the product. Such wheels are somewhat more expensive than modifications equipped with a ceramic abrasive. But this is not surprising, because in addition to excellent elasticity, they also have increased wear resistance.

Features of the choice of tool

The main criterion for choosing a grinding stone is its hardness. This indicator should not be less than the hardness of the part itself being processed. Moreover, it is not permissible to allow large differences in such parameters, which is fraught with possible overheating of the surface.

An important criterion when choosing an abrasive can also be called grain size. Usually, to determine the optimal grain size, it is necessary to familiarize yourself with the requirements for the purity of the finished product. Each grinding wheel is equipped with its own marking, the decoding of which allows you to choose the right sanding tool. It is usually represented by the type of abrasive material, the degree of imbalance, size and type, structure, degree of hardness, level of accuracy, grain size, nature of the bond and maximum processing speed.

When working with metal and wood, it is necessary to use grinding wheels of different grain sizes, otherwise the quality of the finish may be poor. If jags or rough strokes are detected on the surface of the workpiece, it can be confidently asserted that the choice of the grain size of the equipment was made incorrectly.

For the convenience of using the tool, a table of the grain size of the grinding wheels has been created, which allows you to quickly figure out the necessary parameters and decide on the choice of a nozzle.

The most popular types of such a tool include grinding wheels with the following designations:

  • with grit 120;
  • with grain size 60;
  • grit 100.

Depending on the specific type of operation being carried out, the master selects the required type of equipment. For rough grinding, wheels with large fractions of grains are usually used, and for finishing this figure should be much lower. In addition, when selecting a tool, the features of the grinding equipment mode and the technical properties of the cutting element are taken into account.

When working with soft materials, do not use rubber and ceramic discs with large fractions... Fine-grained attachments are used only for polishing. Usually abrasives with small grains are applied to metal discs as well as cutting discs. It is logical to use a fiber wheel to ensure a glossy surface. In this case, the processing result will be better when choosing a tool with a softer tip than the material of the part with which manipulations are carried out. However, this is also often accompanied by rapid tool wear.

When working with large surfaces, you should stop the choice on grinding wheels large diameter... Such a recommendation will save equipment, because a small element will need to rotate much more often, which will lead to its rapid deterioration.

Approaching the choice of a grinding wheel thoroughly, you can find a tool that will show itself in the work as efficiently as possible at the lowest financial cost.

Grinding wheels are designed to remove small amounts of material from the surface of the workpiece. In this way, irregularities are removed, sharpening of various tools is performed. To choose a particular model, you should familiarize yourself with the classification and types of grinding wheels.

Purpose of grinding wheels

The scope of these tools for processing is wide. They differ not only appearance, but also by the manufacturing method. With the help of grinding wheels, you can remove a small volume from the surface of the workpiece, thereby improving the technical and operational characteristics, appearance.

Many materials and tools fall under the definition of a grinding wheel. Therefore, it is advisable to consider the most common of them. For domestic purposes, the end ones are most often used, which are installed on a drill. In addition, one should take into account the marking of the product, the possibility of using it on special sharpening machines, the size.

Methods of using grinding wheels, depending on marking and composition:

  • grinding of surfaces of various parts and workpieces. The degree of processing depends on the grit size, the total contact area and the speed of rotation;
  • sharpening of tools. To perform these steps, you must use special diamond sharpeners.

The material of the blank is taken into account during the selection. For processing wood, steel and polymer surfaces using a drill, they are used Various types grinding wheels.

Some types of work sometimes require grinding wheels of non-standard configurations and sizes. In other models, they differ not only in grain, but also in shape. Most often, these models are used to complete factory machines.

Types of grinding wheels

To determine the types of grinding wheels, you must familiarize yourself with GOST 2424-83. It indicates the area of ​​destination, material of manufacture and requirements for the technical parameters of this type of tools. But the operating conditions are the determining factor.

Currently, the following types of face and plane wheels with the appropriate marking and designation can be used to perform grinding work:

  • grinding for metal. They are used for processing welded joints. After installation on the drill with the end part, the workpieces and parts are processed;
  • diamond. Designed for final grinding of the workpiece surface. It should be remembered that they belong to the category of sharpeners. They are characterized by a special composition;
  • fiber. It is made of multi-layer vulcanized paper. Processing takes place both with the end and plane part of the material. Designed for installation on a drill;
  • petal. Consist of a plurality of petals mounted on a mounting ring. They are characterized by high adaptability to any type of workpiece surface. Rust is effectively removed with petal discs;
  • self-engaging. They are characterized by a high grain size. One part has an adhesive base for installation on a drill. Designed for fine processing of wood or metal surfaces.

Before choosing, consider the grit size of the grinding discs. The same applies to sharpening models. The larger the grain size, the more intensively material will be removed from the surface of the part during processing with a sharpener.




Diameter is also taken into account. For household machines, models with a diameter of 50 to 300 mm are used. Special shaped circles can be installed during fine processing.

Grinding wheel material

The degree of processing of a grinding wheel largely depends on its structure. Given the various types of operations, manufacturers offer several types for drills, differing in marking, material of manufacture and type of processing - end or plane.

The main requirement for the material of manufacture is abrasive properties. At the same time, they must have sufficient mechanical strength, not be destroyed under the influence of aggressive media. The latter quality is especially important when using coolants. This is not the case with petal models.

The structure and composition of the material of manufacture can be determined by marking and designation. The area of ​​application of the grinding wheel is also indicated there:

  • electrocorundum. They are divided into white (22A, 23A, 24A, 25A), normal (12A, 13A, 14A, 15A, 16A), chromium (32A, 33A, 34A), titanium (37A) and zirconium (38A). The higher the number, the higher the workmanship;
  • silicon carbide. Available in green (62C, 63C, 64C) and black (52C, 53C, 54C, 55C) colors. The first has a more fragile structure. Used as sharpening tools;
  • diamond. The main area of ​​application is sharpening and grinding of carbide tools. Diamond wheels can be used to refine other types of grinding surfaces;
  • elbor. Its properties are close to diamond, but it is more heat resistant. For household needs, it is practically not used as a sharpener, since it has a high cost.



The next property of end wheels for a drill is their graininess. It determines the cleanliness of the resulting surface. In the old GOST, the main characteristic was the grain size. This characteristic can vary from 20 to 200 microns. The grain size according to GOST 52381-2005 is designated Fx (where x is a characteristic of the grain size). The higher this value, the smaller size particles.

In each case, the material of manufacture of the grinding wheel for face machining with a drill is determined individually. This is influenced by the properties of the workpiece, the required degree of its grinding.

Marking of main grinding wheels

To choose optimal models of the grinding wheel, you need to know the symbols on its surface. Thus, you can find out not only the method of its manufacture, but also the grain size, exact dimensions and configuration: petal, ordinary or special sharpening.

First of all, you should determine the material of manufacture and the possibility of using it as a sharpener on the machine. Data can be taken from the list described above. Then the graininess of the circle for the drill is recognized. In some cases, the pictogram indicates the impossibility of facing. Most often this applies to corundum discs for metal.

Another property is the hardness of the grinding wheel. Classification depending on its composition:

  • F, G. Belong to the category of very soft;
  • H, I, J. Soft, designed for finishing parts;
  • K, L. Thus, products with medium softness are marked;
  • M, N. Medium, the most common type;
  • O, P, Q. Medium hard;
  • R, S. Solid;
  • T, U. Very hard, used as a sharpener;
  • V, W, X, Y, Z. Extremely hard.

Manufacturers rarely indicate the structure and composition of the disc on the label. This primarily refers to the type of communication. This term indicates which composition was used to create a homogeneous mass. At present, ceramic, bakelite and vulcanite bonds can be used as a binder.

During operation, the geometry of the oval circle or the size of the petal base may be violated. This is especially true for facing parts with a drill or machine. In this case, it is necessary to make corrections according to the marking. It is recommended to use carbide tools or diamond discs for this.

The video material shows the main types of grinding wheels:

What are abrasive wheels - materials of manufacture and application technology. An abrasive wheel is nothing more than a mechanized sanding block. It is made from grains of abrasive materials mixed with a binder.

The resulting mass is pressed into the required shape and fastened under pressure at high temperature... For use, it is enough to have any rotating drive with an electric motor (or other propeller), on the axis of which the disk is attached.

Wide selection and different options application

The main types of abrasive wheels

Types of abrasive wheels and basic surface treatment methods.

Let's consider the most popular ones:

  • cylindrical grinding - surfaces are processed, the cross section of which is perpendicular plane to the axis of rotation is a circle;
  • flat grinding - processing of any flat surfaces;
  • centerless grinding - as a rule, it is used in enterprises engaged in the processing of external and internal surfaces, such as: camshaft shafts, bearing cages;
  • abrasive wheels cut and cut blanks;
  • abrasive lapping of surfaces (for example, the seat and needle of a diesel injector);
  • honing - processing of round surfaces (holes) using special honing heads. It is used when processing cylinders of engines or
  • surfaces of hydraulic pumps;
  • polishing wheels - used to give the surface a slight roughness and mirror shine;

Cut-off

Designed to cut hard materials with little effort. Most often they are used in manual angle grinders (grinders), but they can also be installed on stationary cutting devices.

They are a flat (up to several millimeters thick) disc made of abrasive material, bonded with a bunch and reinforced with reinforcement.

The working edge of the disc scrapes the chips from the surface of the material being processed, forming a cut. In this case, the diameter of the disc decreases, and the surface always remains ready for work, i.e. the disk is self-sharpening.

Subdivided according to the type of processed material:

  • used for cutting pipes, profiles and sheet metal;
  • for concrete and reinforced concrete, when cutting grooves in concrete structures;
  • work with stone, to give the necessary shape to workpieces made of stone and ceramics;

The variety of sizes is impressive

Grinding wheels

Used for emery. With the help of such discs, you can sharpen tools made without the use of hard alloys, as well as finishing workpieces of various shapes.

Cutaway grinding wheels are of the following geometrical shape:

  1. Straight profile. They are used for sharpening knives, axes, external and internal grinding, roughing and cleaning work. You can grind with a plane.
  2. Tapered profile. They are used for sharpening the teeth of non-circular saws.
  3. Double-sided tapered profile. They are used for finishing the profiles of shavers and chisels, gear wheels, and grinding threads.
  4. Straight profile with groove, one or two-sided. They are used for round, surface and internal grinding, neck and face grinding.
  5. One-sided or two-sided tapered groove. They are used for trimming the end face with simultaneous round grinding, as well as round neck and face grinding.

Cup

Subdivided into:

  1. Cylindrical. They are used for surface grinding with the end part and sharpening of the teeth of cutting tools, for example, circular saws.
  2. Conical. They are used for grinding flat guides and sharpening cutting tool teeth.
  3. Poppet. They are used for processing and sharpening multi-edge cutting tools and finishing grinding of gear teeth.

Conical Grinding Stones

For household grinding machines, as a rule, universal emery wheels of a straight profile are used, which can be easily changed to cup wheels if necessary to sharpen a circular saw. In general, the main advantage of abrasive wheels is their wide range of applications.

note

Having a primitive grinding machine and a minimal set of emery in your home workshop, you can perform almost any work on sharpening, finishing and grinding products from the most different materials.

Abrasive grinding wheels, when used correctly, require some tooling to secure the work surface, or at least guides.

Choosing an abrasive wheel

For the right choice abrasive tool, it is necessary to know well the capabilities of the grinding machine - power, working speed, the possibility of their adjustment. Also, for different types the surface to be treated should be of the appropriate type of emery.

IMPORTANT! You can not use the grinding wheel, which will be "at hand". Always check that the emery is suitable for the material being cut.

You also need to know if the work requires cooling and lubrication of the working surface of the grinding wheel. If the requirements of the manufacturer of the abrasive are not met, you can quickly disable the emery wheel itself and spoil the workpiece. It is important to select the correct grit size for the abrasive wheel.

- goods for stone processing.

Grinding disc - one of the types of abrasive tools, along with heads, segments, bars, abrasive belts and abrasives, is actively used for processing various types of surfaces. Abrasives used for the manufacture of grinding wheels are strong, high-hardness substances: diamond, corundum, quartz, as well as artificial materials - electrocorundum, synthetic diamonds, silicon carbide and boron, and others. The grains of these substances are subjected to machining the surface of other materials, in terms of their purpose, they can be compared with the teeth of a conventional saw, but located not along the edges, but along the perimeter of the disk. Grinding wheels are used to process many materials: carbon steel, glass, plastic, bronze, wrought iron and non-ferrous metals. In addition, they are used in tools for cutting brick, stone, ceramic tiles, drywall.

A non-professional classification, familiar to many, divides grinding wheels into the following types:

  • Discs with the so-called "Velcro" - a special fabric that is applied to abrasive paper.
  • Flap wheels - have a surface made of abrasive material, located in the form of a fan overlay of layers. They are very durable, provide a smooth surface after processing, and are most often used for grinding pipes or wood surfaces.
  • Fiber discs made of vulcanized paper with a multi-layer structure. They are attached to the machine using a support plate with the required section. Fiber discs are used for cleaning metal, wood, steel products.
  • Diamond wheels used for finishing. As a rule, they have little strength.

Grinding wheel marking

The quality characteristics of abrasive wheels are regulated by GOSTs, standards and technical conditions... Each of the grinding wheels has its own marking according to the following characteristics:

  1. Grinding material
  2. Disk size
  3. Grain size
  4. Disc type
  5. Hardness
  6. Binder
  7. Instability class
  8. Structure
  9. Segments
  10. Optimum rotation speed

To decipher these points, it is necessary to consider the marking of the grinding wheels in more detail.

Grinding Abrasive Type

The most common marking of abrasive wheels by type of material is the following:

  • Electrocorundum

Marking 12A, 13A, 14A, 15A, 16A: normal electrocorundum (material with high heat resistance, good adhesion to the binder, mechanically strong grains). It is used for processing wrought iron, cast iron, steel, bronze, chrome-plated steel.

22A, 23A, 24A, 25A: white fused alumina (more uniform than type 14A, harder, with sharp edges, self-sharpening, provides a more uniform surface of the material being processed). It is used for sharpening and grinding tool steel, thin-walled parts and tools, as well as finishing and finishing.

Abrasive wheel marking

32A, 33A, 34A: chromium electrocorundum.

37A: titanium fused alumina.

38A: zirconia. The higher the marking, the higher the strength of the discs.

  • Silicon carbide

Marking 52-55С: black silicon carbide (has increased hardness and brittleness in comparison with the previous type of abrasive). They are used for polishing cast iron, granite, porcelain, silicon, ceramic, glass surfaces, as well as viscous aluminum, copper, rubber materials, heat-resistant steel products.

Marking 62C, 63C, 64C: green silicon carbide. Differs from black in greater fragility.

  • Elbor

Marked CBN, CBN, Cubonite, Borazon: Has the strength of a diamond but is more heat resistant.

  • Diamond

Diamond wheel marking: AC2 (normal strength), AC4 (increased strength), AC6 (high strength), AC32 (single crystals), AC50, ARB1, ARK4, ARS3. They have the highest wear resistance, strength, and low brittleness. The use of diamond wheels finds itself in the processing of brittle and high-hardness alloys (cast iron, ceramics, silicon, optical glass), as well as finishing grinding, cutting, sharpening of carbide tools.

Grinding wheels, grit (marking)

A characteristic such as grain size determines the smoothness of the processed surface. The grain size of the grinding disc determines its wear rate, the thickness of the removed metal layer in one pass, etc. The smaller the value of one grain, the smoother and cleaner the surface will be.

The grain size determines the marking of the discs:

  • Grinding grain: the size of the fraction is from No. 200 to No. 16
  • Grinding powder: No. 12-4
  • Microsection powder: М63-М14
  • Fine micro-grinding powder: M10-M5.

The grain size units are given in microns. The marking of diamond grinding wheels, more precisely, the type of their grain size, is indicated in a different way (through the fraction of the upper and lower values).


Grinding wheel grain markings

Circle size

The sizes of the disks are regulated by GOST 2424-75. Marking D is a numerical designation of the outer diameter, d is the inner diameter, h is the height (width). The outer diameter can vary from 3-1100 mm, the inner diameter is from 1.0 to 305 mm, and the height is from 0.18 mm to 250 mm.

Instability class (imbalance)

There are four classes of imbalance (from 1 to 4), i.e. admissible values ​​of the disc deviation from the static balance. The imbalance class refers to the ratio of the mass of the abrasive disc to the accuracy of its geometric shape. Therefore, imbalance and accuracy markings are often indicated side by side. Accuracy class A is used to work on high-precision equipment, class B is more versatile, AA - discs of ideal shape and geometry made of very high quality abrasive.

Structure

The density of the structure is indicated depending on the ratio of the number of abrasive grains to the volume of the disc. The more abrasive per unit volume of the grinding wheel, the denser its structure. If the tool is sharpened, a disc with a less dense structure is more susceptible to cleaning the surface from material particles, creates less risk for deformation, and cools faster.

The numerical designation of the structure is as follows:

1,2,3,4 - dense structure;

5,6,7 - medium density;

8,9,10 - open;

11.12 - porous.


Grinding wheel markings: old and new, the difference is according to GOST

Conventional disc indicators until 2008 were regulated in accordance with GOST 2424-83. A new version of GOST 2424 entered into force in 2008. In 2009, marking of abrasive wheels began in a new way: modern standards for the symbolic designation of the hardness of the processing tool (GOST 52587-2006 instead of the old GOST 18118, 19202, 21323), grain size ( GOST 52381-2005 instead of GOST 3647-80), bundles (new GOST 52588-2006).

Also, modern indicators of the types of grinding wheels differ from those adopted in the USSR. The existing designation of grinding wheels is as follows (the previously used designation is indicated in brackets):

  • - a section of a circle of a straight profile (PP). Suitable for universal use

5 - straight profile with one-sided groove (PV). It is used for cylindrical grinding.

7 - with two undercuts (LDPE)

10 - with hub and double-sided groove

  • - ring type (K)

6 - cylindrical cup-shaped (CC). Used for sharpening tools.
36 - with fasteners (PN)

11 - conical cup shape (CC)

41 - cut-off disc type

4 - with a conical profile of double-sided type (2P)

  • - type with conical profile (3P)

12.14 - plate-shaped (T, 1T).

Flap wheels are marked with the type, outside diameter, inside diameter, height, grain size and sanding paper series.

Bond type marking

The bond holds the grinding grains together with the backing and with each other. Usually, three types of bond markings are indicated on discs: volcanic, ceramic and bakelite.

The first type of ligament is denoted as R, or the obsolete designation is "B". It consists of a vulcanized synthetic rubber.

The ceramic bond is marked as V, the former name is "K". It includes a combination of inorganic substances (clay, quartz). Its advantages are wear resistance, thermal and chemical resistance, but at the same time fragility.

The bakelite bond is marked as B, formerly known as "B4" and "BU". It contains artificial resins. This is an elastic bond, but otherwise the parameters are lower than that of a ceramic bond.

Hardness indicators

The hardness index of the grinding wheel indicates the strength of retention of the grains by the binder on the surface when the abrasive being processed is applied to the disc.

The hardness designations of the disc start from very soft (BM1, BM2) to extremely hard (HR), in the new designation the marking is carried out with letters english alphabet ranging from F (very soft) to Z (extremely hard).

Most often, discs of medium hardness are used, but the choice of the type of degree depends on the type of work performed, the surface of the material, the tool itself.

Grain

According to the previously valid GOST, the marking of the degree of granularity was expressed in measuring the number of grains in a volume of 10 microns; for micro-grinding powder, these values ​​were expressed by adding the letter "M". The new standard establishes the designation with the letter "F" with the addition of a number that indicates the degree of grain. The larger it is, the less grain and vice versa.

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