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 supply it with the necessary specific situation technical characteristics.
This tool is widely used both in processing elements of interior items and for fitting, for example, bar and panel parts of industrial production. Making moving parts smooth is especially important, since ensuring that their friction is minimized plays a large role in the operation of all equipment.
A fairly wide range of materials can be sanded. 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 a final finish by cutting heads.
Often, grinding wheels are used not only to smooth metal surfaces, but also to remove rusty deposits from parts, which is almost impossible to do without this equipment. In many cases, craftsmen purchase abrasive wheels for sharpening machines, with the help of which they can quickly make other cutting tools.
These products have gained particular popularity among jewelers, who primarily polish 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 during the process repair work, for example, when cleaning walls for subsequent tiling. Certain types of circles, when installed on an electric sharpener, allow you to clean pipes from corrosion, remove old paint from plumbing fixtures, etc.
Types of equipment
To carry out the correct processing of parts, it is necessary to decide on the type of grinding. Thanks to this, you can choose the optimal abrasive attachment option.
The main criteria for choosing this equipment include the following components:
- the material from which the workpiece is made;
- the nature of the work exerted on the surface of the product.
Grinding wheels equipped with a ring or straight profile are often used for work on small emery surfaces and machines, in everyday life, as well as for sharpening carried out with the end surface of the tool. The materials used with this equipment are stone, porcelain and glass.
The most popular are conventional and double-sided conical wheels, the operation of which is based on processing the surfaces of the part with a plane. They also allow making cuts in a wide range of materials.
Often experienced craftsmen have in their arsenal cup wheels and tools with all-metal disc attachments equipped with diamond coating. The cup modification resembles straight profile equipment with a conical groove. It differs only in the rectangular arrangement of the end in relation to the side plane.
If we consider the types of equipment depending on the type of abrasive, we can distinguish a fairly wide range of tools. In addition to the above-mentioned diamond coating, which is usually used for sharpening and finishing carbide elements, electrocorundum is considered quite popular, making it possible to produce one-piece attachments. Corundum wheels are usually made without a pressed core and base.
An abrasive called elbor has particular strength. The basis of this material is cubic boron nitride, which is practically not inferior in its performance characteristics to diamond. Moreover, he has an undeniable advantage, namely: high level heat resistance.
The technique of performing diamond spraying on abrasive attachments does not involve the use of any binding elements, since it is applied to the metal in a thin layer. This is what accounts for the significant high cost of such equipment. Abrasive wheels, which have less strength, are made using a ceramic binder 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. Thanks to this, the final product becomes rigid.
There are two main types of nozzles depending on the binder component in the abrasive:
- bakelite;
- volcanic.
The most popular are bakelite attachments, which include an artificial resin that gives the circle the necessary firmness and elasticity. However, the designated component also causes a decrease in wear resistance, which occurs due to insufficient bonding of the grains. This is not observed with wheels on a hard ceramic base. However, it is worth remembering that hard substrates with high hardness can provoke overheating of the metal being ground, and this can lead to burnout of the surface of the workpiece. There is no such drawback in bakelite nozzles. They are quite soft, do not heat the metal very much and self-sharpen during operation.
Wheels with a vulcanite component are even softer. They use heat-treated synthetic rubber as an abrasive element. In the production process of the equipment, the vulcanization method is used, which formed the basis for the name of the product. Such wheels are somewhat more expensive than modifications equipped with ceramic abrasive. But this is not surprising, because in addition to excellent elasticity, they also have increased wear resistance.
Features of choosing a tool
The main criterion for choosing a grinding stone is its hardness. This indicator should not be less than the hardness of the part 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 establish optimal size grain, it is necessary to familiarize yourself with the requirements for the purity of processing of the final product. Each grinding wheel is equipped with its own marking, the decoding of which allows you to select the correct sanding tool. It is usually represented by the type of abrasive material, degree of unbalance, size and type, structure, degree of hardness, level of precision, grit size, nature of the bond and maximum processing speed.
When working with metal and wood, it is necessary to use sanding wheels of different grain sizes, otherwise the quality of the finish may be poor. If you find nicks or rough marks on the surface of the element being processed, you can confidently say that the choice of the grain size of the equipment was made incorrectly.
For ease of use of the tool, a table of grinding wheel grain size has been created, which allows you to quickly understand the necessary parameters and decide on the choice of attachment.
The most popular types of such tools include grinding wheels with the following designations:
- with grit 120;
- with grit 60;
- with 100 grit.
Depending on the specific type of operation being performed, the specialist selects the required type of equipment. For rough grinding, wheels with large grain fractions are usually used, but for finishing grinding this figure should be significantly lower. In addition, when selecting a tool, the features of the grinding equipment mode and technical properties cutting element.
When working with soft materials, do not use rubber and ceramic wheels with large fractions. Fine-grained nozzles are used only for polishing. Typically, fine grit abrasives are applied to discs. metal nozzles, as well as cutting discs. To ensure a glossy surface, it is logical to use a fiber wheel. In this case, the processing result will be better if you choose a tool with a softer nozzle than the material of the part being manipulated. However, this is also often accompanied by rapid tool wear.
When working with large surfaces, you should opt for grinding wheels large diameter. This recommendation will allow you to save equipment, because a small element will need to rotate much more often, which will lead to its rapid deterioration.
By approaching the choice of a grinding wheel thoroughly, you can find a tool that will perform as efficiently as possible at the lowest financial cost.
Grinding wheels are designed to remove small amounts of material from the surface of a workpiece. In this way, irregularities are removed and various tools are sharpened. To select a particular model, you should familiarize yourself with the classification and types of grinding wheels.
Purpose of grinding wheels
The scope of application of these processing tools is wide. They differ not only appearance, but also the manufacturing method. Grinding wheels can remove a small amount from the surface of the workpiece, thereby improving technical and performance 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, end-mounted ones are most often used, which are installed on a drill. In addition, you should take into account the product labeling, the possibility of use on special sharpening machines, size.
Methods of using grinding wheels depending on marking and composition:
- grinding the surfaces of various parts and workpieces. The degree of processing depends on the grain size, total area contact and rotation speed;
- sharpening of tools. To perform these actions, you must use special diamond sharpeners.
During selection, the material of the workpiece is taken into account. Various types of grinding wheels are used to process wood, steel and polymer surfaces with a drill.
To perform certain types of work, grinding wheels of non-standard configurations and sizes are sometimes required. In other models they differ not only in grain size, but also in shape. Most often, such models are used to complete factory machines.
Types of grinding wheels
To determine the types of grinding wheels, you need to familiarize yourself with GOST 2424-83. It indicates the area of purpose, material of manufacture and requirements for technical parameters this type of instrument. But the operating conditions are the determining factor.
Currently, the following types of face and plane wheels with appropriate markings and designations can be used to perform grinding work:
- grinding for metal. Used for processing welded joints. After installation on the drill, the end part processes workpieces and parts;
- diamond Designed for final grinding of the workpiece surface. It should be remembered that they belong to the category of sharpening ones. Characterized by a special composition;
- fiber. Made from multi-layer vulcanized paper. Processing occurs with both the end and planar parts of the material. Designed for installation on a drill;
- petal. They consist of many petals mounted on a mounting ring. They are characterized by high adaptability to any type of workpiece surface. Flap discs effectively remove rust;
- self-hinging. Characterized by a high grain size. One part has an adhesive backing for installation on a drill. Designed for fine processing of wooden or metal surfaces.
Before choosing, consider the grain size grinding discs. The same applies to sharpening models. How larger size grain - the more intensively the material will be removed from the surface of the part during processing with a sharpener.
The diameter is also taken into account. For household machines, models with a diameter from 50 to 300 mm are used. During fine machining, specially shaped wheels can be installed.
Material for making sharpening grinding wheels
The degree of processing of a grinding wheel largely depends on its structure. Considering the different types of operations, manufacturers offer several types for drills, differing in markings, material of manufacture and type of processing - face or plane.
The main requirement for the manufacturing material is abrasive properties. At the same time, they must have sufficient mechanical strength, do not collapse under the influence aggressive environments. The latter quality is especially important when using coolants. This is not typical for petal models.
The structure and composition of the manufacturing material can be determined by markings and designations. The scope 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), chrome (32A, 33A, 34A), titanium (37A) and zirconium (38A). The higher the number, the higher the quality of workmanship;
- silicon carbide. Manufactured in green (62С, 63С, 64С) and black (52С, 53С, 54С, 55С) 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 polish other types of grinding surfaces;
- elbor. Its properties are similar to diamond, but it is more heat resistant. For household needs It is practically not used as a sharpener, since it has high cost.
The next property of end wheels for drills is their grain size. It determines the cleanliness of the resulting surface. In the old GOST, the main characteristic was grain size. This characteristic can vary from 20 to 200 microns. Grit 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 specific case, the material for making a grinding wheel for face machining using a drill is determined individually. This is influenced by the properties of the workpiece and the required degree of grinding.
Marking of main grinding wheels
In order to choose the optimal grinding wheel model, you need to know the symbols on its surface. In this way, you can find out not only the method of its manufacture, but also the grain size, exact dimensions and configuration: flap, regular or special sharpening.
First of all, you should determine the material of manufacture and the possibility of using it as a sharpener on a machine. Data can be taken from the list described above. Then the grain size of the drill wheel is determined. In some cases, the pictogram indicates that face machining is not possible. Most often this concerns corundum discs for metal.
The next property is the hardness of the grinding wheel. Classification depending on its composition:
- F, G. Classified as very soft;
- H, I, J. Soft, designed for finishing parts;
- K, L. Products with medium softness are marked in this way;
- 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. First of all, this relates to the type of connection. This term indicates what composition was used to create a homogeneous mass. Currently, ceramic, bakelite and vulcanite binders can be used as a binding component.
During operation, the geometry of the oval circle or the size of the petal base may be disrupted. This is especially true for face machining of parts using a drill or machine. In this case, it is necessary to make changes according to the marking. To do this, it is recommended to use carbide tools or diamond discs.
The video shows the main types of grinding wheels:
is an abrasive tool consisting of grains of a certain fraction cemented together with a binder. It is a body of rotation with a standard outer and inner diameter, with a certain surface configuration optimal for performing certain operations.
Scope of application
Grinding wheels are used for preliminary and finishing products made of ferrous and non-ferrous metals, plastic, wood and other materials. The area of application of the wheel is determined by its grain size, diameter and surface shape. Using a circle, it is possible to process flat and shaped surfaces, ends, threads, holes, etc.
The main area of application of grinding wheels is mechanical engineering and machine tool construction. Depending on the geometry, they can be used as equipment for sharpening machines, hand-held electric or pneumatic tools. They can also be used for manual operations. A wide selection of tools allows you to carry out a wide range of operations - from roughing and rough finishing to finishing grinding and polishing.
Grit size of grinding wheels
Grit size is one of the main parameters for choosing a grinding wheel for certain operations. It is determined by the grain size of the fraction divided into fractions in accordance with the group of grinding material and is indicated by the corresponding numerical value.
There are three main groups - grinding grain, grinding powders and micro-grinding powders. In the first two groups, grain size is determined by the smallest grain fraction in hundredths of a millimeter. So, for example, 40 means a fraction size of 400 microns or 0.4 mm. In the third group, micro-grinding powders, numeric value determines the largest grain size in a fraction in microns and has an additional designation M. For example, M20 is a circle with largest size grains in a fraction of 20 microns.
The table below shows data on the grain size of the groups in accordance with GOST 3647-80 and international standard ISO 8486.
Profile
The profile of a wheel determines whether it can be used for certain operations. We list the most commonly used types of profiles:
- Flat with a straight profile - internal or centerless grinding, torus processing and other operations.
- Flat double-sided with a conical profile – processing of gears and simple threads.
- Flat with undercut – cylindrical grinding, end trimming.
- Cylindrical and conical wheels – sharpening of tools and other operations.
- Disc wheels – sharpening of tools with multiple cutting blades.
Marking
The main parameters of the circle can be determined by its symbol, which is indicated in the product labeling. Symbol corresponds to GOST R 52781 and it states:
- circle type;
- material;
- grain;
- geometric parameters(outer and inner diameter, height);
- type of ligament;
- structure and degree of hardness;
- the highest permissible processing speed.
The exception is wheels with individual markings, which have wheels from foreign manufacturers. By purchasing this product It is necessary to study the information in catalogs and on packaging.
Selection rules
The main factor in choosing a grinding wheel is the parameters of the material being processed and the scope of application (machine, hand tool). Another important factor is the quality of processing, determined by the grain size of the wheel. The larger the grain size, the higher the surface layer removal rate, but the lower the surface quality. For this reason, fine-grit wheels are used for fine grinding.
The table below provides data on the choice of grit depending on the grinding operation.
It is desirable that the circle matches the material for which it is intended. This is indicated in the manufacturer's recommendations, in particular in the form of an image on the label. Pay attention to the permissible rotation speed, which is an important condition work safety.
GOST standards
Operation and technical specifications adjusts grinding wheels whole line Russian and international GOSTs. In particular:
- GOST 3647-80 and the corresponding ISO 8486 regulate the grain size of the wheels.
- GOST R 52588-2011 – defines the safety requirements for the tool.
- GOST R 52781 – regulates the technical conditions of grinding wheels.
There are other standards that define the parameters various types grinding wheels.
Before it becomes a finished product, a metal blank is very often processed using abrasive grinding wheels. This is done in order to ensure a highly smooth surface.
Scope of application of abrasive grinding wheels
Polishing any elements not only makes them more attractive in appearance, but is also often a necessity from a technical point of view. In everyday life, elements of interior items are often subjected to this process, and in industrial production– parts of various machines, machine tools and other mechanisms.
For moving parts, polishing is extremely important: individual parts should be well fitted and smoothed to minimize friction. It is worth noting that the most different materials– metal, stone, plastic, wood. Abrasive wheels are also actively used in a variety of sharpening machines.
Abrasive wheels can vary in shape as they are used for different purposes. In addition to smoothing the surface metal parts often need cleaning to remove rust. It is almost impossible to implement this task without special circles. By means of removable attachments for grinding machine you can make recesses and grooves of varying complexity in various materials, including non-ferrous metals, ornamental stone, concrete walls, soft alloys.
Abrasive wheels are very popular among jewelers, for whom polishing items made of precious metals is the main part of their work. Stone craftsmen who work with ornamental minerals and semi-precious stones also use this tool.
There are special types of grinding attachments installed on the drill. They are actively used during repair or finishing works(for example, for cleaning the surface of walls before laying tiles or applying plaster compositions). Some grinding wheels are excellent at removing old paint with plumbing, cleaning pipes from corrosion and other similar work.
Types of Grinding Wheels
To properly process a part, it is necessary to determine the type of grinding. This will allow you to choose the right abrasive attachments. The main selection criteria are the material of the workpiece and the nature of the impact on its surface.
Thus, grinding wheels with a straight or annular profile are widely used in everyday life and on small metals, sharpening operations performed by their end surface. These wheels are relevant when working with glass, porcelain, and stone (here you can also use flat attachments with one- or two-sided grooves, which are also convenient when carrying out grinding work).
The most common are conical circles, which can be either double-sided or regular. They can be used for all of the above work for surface treatment of parts with a plane. They can also be used to make holes in almost any material.
For machining many parts optimal options can be called a grinding cup wheel and a wheel with disc attachments (most often they have all-metal attachments and diamond sputtering). The cup wheel resembles a straight profile tool with a conical undercut. The main difference is that the end is located at a right angle to the side plane.
The range of abrasive wheels by type of abrasive is quite wide. In addition to the previously mentioned diamond coating, electrocorundum is widely used. Solid nozzles are made using electrocorundum. Most often they do not have a base and a pressed core.
Circles made of silicon carbide are also in demand. The latter are divided into two types: black and green (the nozzles have the corresponding color). Green is more fragile.
CBN is a high-strength abrasive. This material is based on cubic boron nitride. By operational properties it is not inferior to diamond, while CBN has a higher level of heat resistance.
Vulcanite and bakelite grinding wheels
Diamond coating has a fairly high cost, so it is applied in a very thin layer on metal base. Abrasive wheels with less strength are formed in a different way. Often for similar purpose binder is used ceramic composition, where the main components are materials of inorganic origin (quartz, clay, etc.). Highly ground, these binders are added to the selected abrasive when forming the wheel, providing finished product increased rigidity, but also corresponding fragility.
Bakelite nozzles are in great demand on the market. They owe their name to the main filler – bakelite (artificial resin). This binding component gives the circle elasticity and a kind of elasticity, but at the same time wear resistance is reduced as a result of weaker fixation of the grains (compared to a rigid ceramic base).
It is important not to forget that a rigid base of high hardness can lead to overheating of the metal being ground and, accordingly, burnout of the surface of the processed element. Bakelite nozzles do not have this drawback. They are much softer, so they heat the metal very little and are capable of self-sharpening when processing a part.
The grinding wheel with vulcanite binder is even softer. Here the main abrasive element is synthetic heat-treated rubber. In other words, vulcanization is used in the production of such grinding attachments, which is reflected in their name. Vulcanite wheels have a higher cost compared to ceramic abrasives. However, despite the increased elasticity, their wear resistance is beyond praise.
Selecting a grinding wheel
The main requirement for an abrasive attachment concerns its hardness. The hardness of the nozzle must be higher than the hardness of the workpiece. At the same time, it is undesirable for these parameters to differ greatly, otherwise the likelihood of overheating of the treated surface increases. One of the most important criteria When selecting an abrasive, its grain size is also considered.
Large fractions of ceramic or rubber wheels are not suitable for working with soft materials. Fine grains are only suitable for polishing. Often, fine-grained abrasives are applied to cutting discs and disc-shaped metal attachments. Glossy surface can provide fiber circle. If its nozzle is softer than the workpiece, the processing result will be good, but the wear of the tool will also be very severe.
Grinding the surfaces of parts made of various materials is understood as the main initial operation for removing burrs, nicks remaining after the operation of various metalworking machines, and sharpening knives. In order to ensure high-quality processing, it is necessary to select a grinding wheel with characteristics that correspond to the type and size of the part undergoing this procedure.
General information
An abrasive grinding tool is actually a type of cutting metalworking equipment. The cutting is carried out using a large number of solid particles. There are a lot of types of grinding wheels, some of which are known only to those who have encountered them. For example, in aircraft manufacturing and space industry used special tool. However, it does the same job as other similar devices.
There is a different type of grinding wheel for different coatings. With their help, steel, cast iron products, alloys of non-ferrous metals and forged accessories can be processed. There is special equipment for working with glass, ceramics and brick. The most common abrasive tools currently in use are:
- In circles.
- Heads.
- Cutters or cutters.
- In segments.
- Bar devices.
After processing with such equipment, the remaining roughness is determined by classes A, B and AA. Best quality grinding, designated by the letters AA, is achieved on high-precision machines.
Classification of sanding tools
Graduation of circles by type occurs in two ways. The first of them is determined by two official documents: the old Soviet GOST 2424-83 “Grinding wheels: technical conditions” and the modern “Grinding wheel: GOST R 52781-007”. However, what is contained in them will be difficult to understand for most untrained users.
For this, there is a second, popular specification of grinding tools:
Product quality characteristics
There are a lot of different parameters by which such products are classified. There are even more types of markings for abrasive wheels due to the fact that there are many different combinations of these properties. The main parameters of abrasive wheels for sharpening machines the following are considered:
A circle with the appropriate indicators is selected for use, which are indicated in the markings on the product itself.
Fixture Grit
This is the most significant characteristic. Its value determines how smoothly the sample will be polished. In addition, the size of wear, productivity, and the thickness of the layer removed per cycle also largely depend on this indicator. The smaller the grain of the tool, the higher the cleanliness of the processing. However, the speed of work with such granularity is reduced. In addition, such devices often cause burns to the part.
The old standard defines the grain size in microns, and is now denoted by the letter F with a number. The higher the digital component, the less grain. All these indicators are summarized in the table of grinding wheel grain size.
Materials for production
Like all characteristics, the requirements for the material from which grinding wheels are made correspond to GOST. Minimum conditions - wear resistance, low heat transfer, hard surface. Based on these conditions, The abrasive tool is made from the following material:
Application of binding materials
For a tight arrangement and protection from destruction, special substances are used in grinding wheels. Their quality, variety, and even distribution affect all the characteristics of abrasive tools. And also the presence of these materials shows the ability to independently sharpen crumbled sections of the grinding stone. If the binding component does not correspond to the surface being processed, the tool loses its main property, wear increases, grains that have not yet been worked are chipped, and burning and clogging appear.
Organic and inorganic binders can be used as binding elements. The first represent ceramic and silicate materials, the second - bakelite and vulcanite.
The following materials are used in a ceramic bond: fire-clay, quartz and spar. They are strong, durable and resilient cutting edge. Tools on this basis can be cooled with special emulsions. Circles of small thickness are destroyed by lateral impact. Designated K0, K1, K3 and so on. In their production, silicon carbide or electrocorundum grains are used. They grind well in all ways, except for cutting and use in narrow grooves.
Powder from bakelite resin and varnish makes up a bunch of B, B1, B2 and others. Such circles are thin, strong and elastic. However, when heated, such a compound floats and the grains fall out. To increase heat resistance, cryolite is added to such a bond. Wetting when grinding with wheels with bakelite bond is prohibited.
A mixture of artificial rubber with sulfur produces a vulcanite binder. Its elasticity is higher than that of bakelite, but its heat resistance is worse. Elasticity makes it possible to produce thin cutting discs with the designations B, B1, B2.
High-strength metal bonds are made on copper, tin, aluminum and other bases. Used in the manufacture of diamond and CBN grinding wheels.
Hardness indicators
This property describes the disc's ability to retain grains when external influence. The lower it is, the faster the destruction of the abrasive occurs. The breakdown of the hardness of grinding wheels for machine tools looks like this:
This parameter is determined by the depth of the sandblasting excavation or a Rockwell hardness tester. Most often used grinding discs average hardness. They are extremely productive and durable. For internal and surface grinding, soft tools are suitable. When turning threads and small-diameter parts, hard circles are needed. As a rule, the harder the workpiece, the softer the abrasive tool needed.
Grinding wheel accuracy
When determining this parameter, existing cracks, cavities and the location of surfaces relative to each other are assessed. The most accurate accessories have minimal inconsistencies and are installed on precision machines high precision processing and high-speed equipment. Marked with the letters AA.
The next most accurate abrasive devices are slightly inferior to the highest quality ones. They are designated by the letter, A. Samples of the lowest accuracy category are one and a half to two times inferior to accessories of class A. They are marked with the letter B and are used for less precise grinding operations.
Abrasive size
This parameter is observed in accordance with GOST 2424-75. The dimensions of the disks are strictly observed. All grinding equipment is developed to these standards:
- The outer diameter of the circle is designated D, its dimensions range from 3 to 1100 millimeters.
- The internal diameter, sizes from 1 to 305 mm, is marked with the letter d.
- Height, or thickness, is h with a value of 0.18-250 millimeters.
Tool instability
This characteristic shows the deviation of the grinding wheel for a sharpener from the rest position - in other words, runout during rotation. In the marking stamp it is indicated next to the accuracy class and has designations from 1 to 4. One indicates the high quality of the equipment.
Surface structure
Its density is determined by the ratio of the number of grains to the volume of the disk. Accordingly, the greater their number and the smaller the coefficient, the denser the circle. A dense surface is designated 1-4, marking 5-7 guarantees an average value. 8-10 is an open structure, and a coefficient of 11 and 12 means a porous type of sandpaper.
Safety at work
Operations involving grinding and cutting equipment have several hazards. This is the rotation of the device, the possibility of destruction of the disk while moving, the threat of touching rotating equipment. To maintain health, you need to fulfill the following requirements:
Modern grinding tools and machines greatly facilitate human work. A right choice equipment will allow you to perform cleaning operations with the maximum level of cleanliness.