What is the grinding wheel made of?
Features of fluid for abrasive grinding wheels
The quality of work and the final result depends on the choice and correct use of the grinding fluid. Coolants are used to lubricate the wheel, reduce and dissipate the heat generated by grinding.
Also, the grinding fluid keeps the abrasive wheel cool and reduces work distortion due to heat or high temperatures. This fluid is excellent at reducing friction between the cutting tool and the chip. It also reduces stress for improved finish and helps keep the workplace clean.
Grinding wheel fluids can be as follows:
- Synthetic shapes. These are formulations without mineral oil. Such liquids dissolve easily in water and form a clear solution. They contain corrosion inhibitors and wetting agents. Notable for excellent cooling and lubricating functions. Such fluids are most often used for machine tools.
- Emulsion. Created by combining two liquids that do not dissolve in each other. Emulsions generally contain a higher proportion of mineral oil. from 30 to 70% with corrosion inhibitors and wetting agents. In appearance, they are opaque solutions of a milky color.
- Semi-synthetic. Combines synthetic and natural emulsifiers. They contain 10 to 30% mineral oil, corrosion inhibitors and wetting agents. Semi-synthetic liquids dissolve in water, forming a translucent consistency.
To choose the right coolant for an abrasive grinding wheel, you need to determine the specifics of the tool, the method of cutting it. The quality of the water used and its hardness also play a role. Determine the degree of surface contamination, filtration system.
Bonding materials in grinding wheels
Grinding performance is highly dependent on the bonding material. There are several types of connecting elements:
- Ceramic bond. To create a strong connection, spar or clay is fired. Consequently, the abrasive grains are bonded together. Glass-bonded products are widely used in the general grinding field. Such products have a large number of pores that are resistant to water and alkalis. They also provide a cooling process that prevents burns.
- Synthetic resin or rubber bonding is achieved through curing or thermosetting Bakelite. Products made from rubber bonds are elastic and have high tensile strength and can be used at high working speeds. The rubber compound is used for thin grinding wheels such as cut-off wheels and pressed center wheels. The only drawback of synthetic resins is that they are exposed to heat and oil. In work, it is important to correctly approach the issue of choosing a grinding liquid in order to prevent danger.
- The rubber method is provided by curing natural or synthetic rubber, hardened in grains. Such circles are susceptible to heat and oil.
- Foaming. In this case, a synthetic resin acts as a binding element. Since the products are highly elastic and water resistant, they are used for sanding non-ferrous materials such as aluminum.
Features of the work of different types of grinding wheels
The grinding process is that the grains are worn out and split off. Since this is an ongoing process, new grains or “cutting edges” are constantly emerging that support the grinding. Self-sharpening cutting edge is the main feature of the grinding wheel, which distinguishes it from other types of cutting discs for angle grinders.
The brand of the grinding wheel determines the scope of its application. Therefore, you must consciously and carefully approach the choice of the circle. Generally, hard material requires a low quality wheel, while soft material is best sanded with a high quality wheel. It is possible to determine whether the grinding wheel is suitable for the intended purpose by looking at the marking. The manufacturer indicates the disc information on the colored side. Most often, encryption is carried out in accordance with GOST, based on which you can determine the disk speed, diameter, materials.
Grit is another important factor when choosing a grinding wheel. The proportion of grain volume in a given volume of the entire grinding wheel is called grain size. The grain ratio is distributed over 15 varieties. This is the structural number of the grinding wheel, which must also be written on the consumable. The larger the number, the lower the grain ratio, that is, the larger the space between the grains. The space between the grains has a great influence on the grinding efficiency and heating frequency.
Abrasive wheels: features, types, purpose
The thread wheel of an abrasive grinding wheel consists of three elements, each of which plays a specific role in the task at hand. Structural elements are considered: abrasive grits, ligaments and pores. The task of abrasive grinding is to cut hardened steel to the correct size and surface finish.
The linking element holds the grinding sleeve in place and ensures a safe grinding process even when the tool is running at high speeds. The pores or grains provide an open structure for the grinding wheel. Due to this property, the coolant enters the working area, and the chips are transferred from the grinding area. Quality abrasive wheels are designed for a continuous grinding process. Because the wheel runs at high rpm, its grains easily grind heavy and tough materials, achieving high precision and excellent quality.
The main rules for working with a grinding wheel
To check that the abrasive sander is correctly installed, run it immediately after attaching it. The wheel must rotate freely at working speed for at least one minute. If you use a sleeve during grinding, it must not extend beyond the grinding disc.
Do not use a disc that is not suitable for your material. Since grinding is not complete without sparks and chip formation, it is important to provide yourself with protective equipment. These include: gloves, clothing, aprons, shoes, glasses. Never use force to stop the grinding wheel. After pressing the shutdown button, the disc should stop by itself. When choosing a grinding wheel, pay attention to the quality of the product according to the GOST marking and the shelf life. Expired discs cannot be used for security reasons. This can lead to breakdowns and accidents.
What does a grinding wheel consist of??
The grinding wheel consists of a grinding grain and a bond. The grinding grain is the cutting component, and with the help of a bunch of grains, the grains are held together during cutting. The amount of bond, grain and free space between them determines the structure of the grinding wheel. When the task is to find a good grinding wheel for hand grinders, then it is worth deciding on the type of material to be processed. The choice of wheel will depend on how the abrasive particles interact with a particular material. Staying sharp is the ability of a perfect abrasive. The number of blunt edges should be kept to a minimum. The types of abrasives differ in such qualities as impact resistance, strength, hardness and resistance to chipping. As a rule, an abrasive grinding wheel is made of aluminum oxide. This abrasive is used for grinding various alloys, carbon steel, wrought iron, high speed steel, ductile iron, bronze and other materials.
There are different types of abrasives that are made from aluminum oxide. Any type of abrasive has a designation, which often consists of numbers and letters. Depending on the manufacturer of the abrasive, this company may have options. There is another type of abrasive. zirconium aluminum oxide, from which a grinding wheel is made. This is a different combination of aluminum oxide with zirconium oxide. The reference of these materials provides a strong and durable abrasive, which is used for rough processing with grinding wheels.
When grinding brass, aluminum, soft bronze, bleached and gray cast iron, grinding wheels with silicon carbide abrasive are used. For sanding hard wood or metal, a velcro abrasive wheel is used. Ceramic alumina is a breakthrough in abrasives. It is very hard and tough, used for grinding difficult-to-cut steels and alloys.
- Scope of application
- Grinding wheel grit
- Selection rules
A grinding wheel is an abrasive tool consisting of grains of a certain fraction, cemented together by a binder. It is a body of revolution with a standard outer and inner diameter, with a certain surface configuration that is optimal for performing certain operations.
The profile of a circle determines whether it can be used for certain operations. Let’s list the most commonly used types of profiles:
- Flat with a straight profile. internal or centerless grinding, torus machining and other operations.
- Flat double-sided with tapered profile. machining gears and simple threads.
- Flat grooved. cylindrical grinding, end trimming.
- Cylindrical and conical circles. tool sharpening and other operations.
- Disc wheels. sharpening tools with multiple cutting blades.
You can determine the main parameters of the circle by its symbol, which is indicated in the product labeling. The symbol corresponds to GOST R 52781 and it indicates:
- circle type;
- geometric parameters (outer and inner diameter, height);
- type of ligament;
- structure and degree of hardness;
- highest permissible processing speed.
The exception is wheels with individual markings, which have wheels of foreign manufacturers. When purchasing this product, you must study the information in the catalogs and on the packaging.
The main factor in choosing a grinding wheel is the parameters of the processed material and the scope of application (machine tool, hand tools). Another important factor is the quality of processing, which is determined by the grain size of the wheel. The larger the grain size, the higher the rate of removal of the surface layer, but the lower the surface quality. For this reason, fine grinding wheels are used for fine grinding.
The table below provides information on the choice of grit depending on the grinding operation.
It is desirable that the circle corresponds to 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 for safe work.
Scope of application
Grinding wheels are used for preliminary and final processing of products made of ferrous and non-ferrous metals, plastic, wood and other materials. The scope of a circle is determined by its grain size, diameter and surface shape. With the help of a circle, it is possible to process flat and shaped surfaces, ends, threads, holes, etc.
The main field of application of grinding wheels is mechanical engineering and machine tool construction. Depending on the geometry, they can be equipped with sharpening machines, hand-held electric or pneumatic tools. They can also be used for manual operations. A wide range of tools allows for a wide range of operations. from roughing and roughing to finishing sanding and polishing.
Grinding wheel grit
Granularity is one of the main parameters for choosing a grinding wheel for performing certain operations. It is determined by the size of the grain, subdivided into fractions in accordance with the group of grinding material and indicated by the corresponding numerical value.
There are three main groups in total. grinding grains, grinding powders and micro-grinding powders. In the first two groups, the grain size is determined by the smallest grain of the fraction in hundredths of a millimeter. So, for example, 40 means a particle size of 400 microns or 0.4 mm. In the third group, micro-grinding powders, the numerical value determines the largest grain size in the fraction in microns and has the additional designation M. For example, M20 is a circle with the largest grain size in the 20 micron fraction.
The table below shows data on the grain size of the groups in accordance with GOST 3647-80 and the international standard ISO 8486.
Vulcanite. perfect metal polishing. Bezhelme.com
Outwardly, they immediately differ from other abrasive wheels, in particular from emery wheels. Those are made of electrocorundum and serve for sharpening metal, removing a certain layer of metal from the surface. For the initial processing, they are, of course, required.
So, we read what the vulcanite grinding wheels are intended for. for clean grinding and polishing of metal. That is, if you grind the metal for a long time with such a circle, then you can even remove hundredths of a millimeter from the surface.
Therefore, they are often used by “sharpeners”. people who sharpen cutting tools. In the household, such a circle will definitely come in handy, with its help you can “direct” shine “on any metal product, it is very convenient to clean off small rust, give shine to stainless steel and ordinary metal products.
For people who decide to make knives on their own, the following set of tools can be recommended for this:
Polished with a vulcanite wheel after having given the final shape to the workpiece. The number of revolutions. 2500-3000 can be considered optimal for metal processing. The rubber wheel perfectly removes all burrs left after turning with a regular abrasive wheel.
After processing with vulcanite, you can refine the part with a felt circle with the applied GOI paste to bring the final shine. After the GOI paste, if you really decided to do everything beautifully, you can polish with various special pastes of very fine grain size 4000 and 5000.
Rubber grinding wheel. Vulcanite. perfect metal polishing. Bezhelme.com
Grinding wheel types
To correctly process a part, it is necessary to determine the type of grinding. This will allow you to select the correct abrasive attachments. The main selection criteria are the material of the workpiece and the nature of the impact on its surface.
So, grinding wheels with a straight or annular profile are widely used in everyday life and on small machines for grinding metals, grinding operations performed by their end surface. These circles are relevant when working with glass, porcelain, stone (here you can also use flat nozzles with one- or two-sided groove, which are also convenient when carrying out roughing work).
Conical grinding wheel
For processing many parts, the best options are a grinding cup wheel and a disc with disc attachments (most often they have all-metal attachments and diamond dusting). The cup wheel resembles a straight profile tool with a tapered recess. The main difference is that the end is at right angles to the lateral plane.
An example of cup grinding wheels
The range of abrasive wheels by type of abrasive is wide enough. In addition to the previously mentioned diamond coating, electrocorundum is widely used. With the help of electrocorundum, one-piece nozzles are made. Most often they do not have a base and a pressed-in core.
Wheels made of silicon carbide are also in demand. The latter are divided into two types: black and green (nozzles have the corresponding color). Green is more fragile.
Elbor belongs to high-strength abrasives. This material is based on cubic boron nitride. In terms of operational properties, it is not inferior to diamond, while Elbor is distinguished by a higher level of thermal stability.
Types and stages of polishing work
There are two main stages of polishing work:
- Abrasive. its main purpose is to get rid of small defects.
- Protective. is carried out for preventive purposes, allowing the paintwork of the car body part, metal parts, headlights and glass to be provided in proper condition.
Polishing includes several phases, each of which has its own type of polishing disc. The closer the process gets to finishing, the lower the abrasiveness of the disc becomes. As a result, the surface of the car will be reflected with a mirror shine. During polishing work, at least 6 discs must be used.
Types of Grinding Wheel (3D Animation)
Polishing discs (felt, rubber) | BATTLESHIP
In order for the car’s appearance to remain attractive for a long time, it is necessary to pay due attention to caring for the “iron horse”. The most common types of work are considered to be polishing the headlights, body and interior. Some car enthusiasts seek professional help, but most still prefer to polish on their own.
Using a grinder, drill or angle grinder, a microscopic layer of the coating is removed, then all irregularities and roughness are removed. In order for the work to be done with high quality, it is important not only to choose the right tool, but also to purchase suitable equipment in the form of polishing wheels.
If it is necessary to polish large surfaces, felt polishing discs, which are large in size and capable of covering large areas of the processed products, will be an excellent solution. For installation in a cam-type chuck, cylindrical discs are used. this shape allows you to process absolutely any parts and elements of complex configuration.
Amazing Idea Of Wastage Grinder Disc
Round flat or cylindrical felt discs are of several types:
- coarse. they are distinguished by increased wear resistance, durability. Designed for roughing or preliminary processing of metal surfaces and parts;
- semi-round Bosch. are actively used not only in the automotive business, but also for the processing of surgical instruments made of stainless steel;
- fine-haired. suitable exclusively for polishing headlights and especially important parts and devices.
To give the car a presentable appearance, coarse wheels with a thickness of 25 mm and a diameter of 71-250 mm are usually used.
It is recommended to polish with felt discs at low tool speeds. Such material tends to quickly become dirty, so it is necessary to store the circles in a clean, dry place, wrapped in paper or a vacuum bag.
Hard Vulcanite Circle
Hard wheels are mostly used for polishing and cutting, but they have some peculiarities:
How to attach a grinding wheel to an angle grinder?
A spacer is placed in front of the circle, the same is used on the other side. This allows for a longer tool life. It is especially worth considering how to fasten the grinding wheel, since its service life depends on the correct fastening.
When attaching the grinding wheel to an angle grinder, it is important that the fasteners are tightened sufficiently, otherwise the wheel will quickly slip off during use. The other extreme is also unacceptable. the circle must rotate freely. If the fasteners are overtightened and because of this a tight move is observed, the grinding wheel will crack very quickly and become unusable.
Grinding wheels. purpose
The answer to the question “What is a grinding wheel for?” assumes a large number of options. The main operations for which the use of grinding wheels is provided are:
- surface cleaning;
- cutting off;
During the operation of the grinding wheels, other tasks associated with cleaning and grinding the surface can also be performed. In most cases, the use of this tool is necessary not only from an aesthetic point of view, but is also prescribed by the technological process to give the surface the necessary properties.
Grinding wheel diameter. how to choose the right one?
When choosing the size of the grinding wheel, two parameters must be considered, in particular:
- The outer diameter of a circle, measured from one edge to the other. For a given size, the circle is chosen based on the tasks set, that is, the size of the workpiece to be processed. It is always advisable to choose the maximum of the possible options, since the peripheral speed of the grinding wheel in this case will be higher, which means that the productivity will also increase.
- The inner diameter of the grinding wheels, that is, the size of the bore at which the wheel is attached to the spindle. The rim diameter of the grinding wheels must necessarily coincide with the one declared by the manufacturer of a particular angle grinder or machine. If it is less, boring will be required, if more, the spindle is wrapped with a special tape until the parameters match. However, any of these actions will negatively affect the quality of the fastening.
When choosing a grinding wheel for grinding machines, diameters play a special role in internal grinding. In this case, the size of the circle is usually 0.7 to 0.9 times the size of the hole. You should not exceed these parameters, since the grinding procedure will be inconvenient, and with a smaller wheel diameter, the speed of its implementation will greatly decrease.
Grinding wheels: application, characteristics, assembly and installation
The use of grinding wheels is a process that requires taking into account the mass of subtleties. The choice can also be difficult, since the number of product types is very significant, and the production of grinding wheels has a vast geography.
How long does the grinding wheel last??
With intensive use, which essentially accompanies the performance of any operation, wear of the grinding wheel is inevitable. In the course of operation, the grains on the outer diameter of the circle are grinded, therefore, it partially loses its abrasive and cutting properties. In this regard, they talk about such a characteristic as the consumption of grinding wheels.
The consumption rate of grinding wheels for a specific task, as a rule, is determined empirically, since it depends on several parameters:
- Material. The harder the material, the faster the disc wears out. In particular, the consumption of grinding wheels per 1m2 for wood will be slightly lower than when working with stone or metal;
- The presence or absence of the self-sharpening function. Wearing out to a certain limit, the grains fall out from the edge, so the circle becomes sharper. In low-quality products, grains often fall out uncontrollably and until they are completely worn out. In this case, they say that the circle is “pouring”.
Reliable manufacturers of grinding wheels
Among the leading wheel manufacturers, both foreign and domestic manufacturers stand out. Italian companies, in particular Bavelloni, Botero and ADI, traditionally hold the palm in terms of quality and variety. In addition to the above advantages, the circles of their production differ in functionality, since in the assortment you can find a product for virtually any task.
A significant disadvantage of “Italians” with all the above advantages is the rather high price. Chinese manufacturers. Zauber and Huater. allow you to significantly save on purchase, while also being distinguished by decent quality.
Among the manufacturers of grinding wheels in Russia that deserve special attention, it is worth mentioning the Luga and Ivanovsky plants (LAZ and ISMA). Their products are in steady demand in the market.
How To Use Grinding Wheel For Angle Grinder?
Abrasive discs can be used on two tools:
- Angle Grinder.
The attachment of the grinding wheel to the latter is carried out on the spindle. The main advantage is the easy replacement of disks, which can be selected and installed for different tasks.
Grinding wheel: types and applications
The grinding wheel is a solid body consisting of abrasive grains of material, which are cemented together with the help of a special bonding agent. Often this is a solid of revolution, which can have different sizes and cross-sectional profiles. Let’s talk in more detail about what abrasive grinding wheels are, what they are and where these or those types are used.
About fiber grinding wheels
This tool is based on vulcanized paper, laid in a large number of layers. Fastening to the machine is realized using a support plate, which has a corresponding diameter. The color of the circle depends on the binder and the grain. Brown circles are used for processing metal, wood and steel. A key feature of fiber discs is that they have to deal with a very narrow range of grain sizes. But even this is quite enough to perform work of varying complexity, ranging from rough roughing and injection by finishing grinding. Most often, such circles are used in mechanical engineering, the production of metal structures. For example, the use of a multi-bond allows high-quality processing of stainless steel. In addition, such wheels provide so-called cold grinding, which is their advantage. But it is worth paying attention to the fact that such a grinding wheel for the machine requires special storage conditions. The humidity should be as low as possible. This is due to the fact that with an increase in this parameter, the fiber wheel collapses and partially loses its performance.
What is a diamond wheel?
In recent years, this tool has gained great popularity. Despite the considerable price, diamond wheels are in great demand for a number of reasons. Firstly, such an abrasive is very wear-resistant, so it can process much more material than the classic version. Secondly, the quality of the work performed is much better and the surface is cleaner, which is extremely important, especially where it is required. The so-called turtle. diamond grinding wheel (flexible). ideal for stripping concrete, granite and other building materials. Usually, the processing process with such a tool is characterized by the fact that the labor intensity is significantly reduced and the speed of execution increases. At the same time, we can talk about reasonable costs. Such a circle wears out much more slowly than a classic one. The diamond tool is also characterized by the fact that it has a low noise level.
It can be said with great confidence that there are now universal circles. most popular. Their versatility lies in their ability to handle a wide range of materials. The simplest example can be given by picking up a circle such as PP. It is suitable for external machining of workpieces with a diameter of 250-1100mm, internal grinding of workpieces up to 1500mm, centerless, flat, grinding of workpieces of various diameters. This makes such circles almost indispensable when performing work of varying complexity. Of course, other materials are used for some other purposes. For example, a circle of type 36 (PN) is used for roughing and very rarely for finishing.
The grinding wheel can be manufactured on a variety of substrates. There are both expensive abrasive materials with a stronger grain and cheaper counterparts. In this case, a variety of binders are also used. Currently, grinding wheels are classified according to a huge number of parameters. It will take a lot of time to describe each of them. Few people have heard of some species, since they have a narrow application. For example, some abrasives are only used in the aircraft industry. Naturally, they have significant differences from the classic options. In general, these wheels are used for grinding parts. Some types allow you to work on the painted surface, others. on a primer. etc. But let’s talk about everything in order.
Velcro sanding discs
This circle got its name because of the way it is attached to the support of a tool or machine. For this, there is a so-called velcro fabric on the surface. It firmly and reliably engages with the hooks of the support, which allows you to efficiently perform work even at high speeds. In fact, these are universal wheels, since they can be used to process almost any material. Such grinding wheels are also marked in a peculiar way. For this, a special dye is applied to them. For example, the most common are brown circles. consist of abrasive grains (aluminum oxide corundum). This allows materials such as metal or wood to be processed. But the blue color indicates that this wheel is intended for grinding stainless steel products. For this, it contains grain. zirconium corundum. Often the circles are of the same color, but different shades. In particular, white products are suitable for lacquered surfaces, paints and putty. But the black color suggests that such a circle can easily process mineral materials.
Often the circle of the desired color is not at hand. In this case, the situation is fixable. The fact is that sticky circles, as noted above, are universal. They are often used not for their intended purpose. But it is also impossible to thoughtlessly use a grinding wheel to work with this or that material. First, you need to take into account the characteristics of the processed material. In particular, hardness and structure play a role. In this case, the hardness of the abrasive wheel used must be greater. In this case, during operation, it will successfully fulfill its main purpose. For soft materials such as chipboard or MDV, the PS18 wheel is suitable. It can also be used to remove rust from metal surfaces. In addition, if the product is used for other purposes, then it is necessary to take into account the revolutions and grain size. In general, it is recommended to use circles only for their intended purpose.
Flap grinding wheel
Abrasive wheels of this kind have a somewhat unusual structure. They consist of fan petals made of abrasive. Such a tool has become very widespread due to its excellent performance characteristics. High elasticity, adaptability to the material being processed and many other advantages make petal circles practically irreplaceable. Previously, such wheels were only used on machine tools and straight grinders, but more recently, wheels for an angle grinder have appeared. True, the choice is still small and is limited to tools of 115 and 125 mm. But this is already enough to carry out a large amount of work. The flap wheel looks advantageous against the background of the two options described above, since secondary burrs are not obtained during the grinding process. We can say that this kind of grinding wheels are very common. Their color marking, as in the previous cases. Often such a tool is used to process pipes and fittings made of metal and wood.
It is quite natural that in the process of performing grinding work, the wheel is deformed. This happens for a number of reasons, which we will not talk about. At the same time, it makes sense to note that editing is often used. It is the process of restoring the geometry of the circle and its performance. Currently, they use dressing by turning, rolling, and grinding.
The first method involves the use of a special ruling tool. Its edge acts as a cutter. This is one of the best solutions because of its simplicity and efficiency. But along with this, the dressing tool is subject to heavy wear, so it is better that it be diamond, in particular, it can be diamond pencils, grains, etc. Dressing grinding wheels by rolling implies the use of dressing discs that rotate in contact with the wheel. This method is good because the wheel is practically not subject to wear.
Now you know what abrasive grinding wheels are and what they are. As for the choice, then you should have a tool at hand that is suitable for performing work with various materials. If you cannot use the circle for its intended purpose, it does not matter, you can try another, but in this case, be careful, since it is very easy to spoil the surface, and it is rather difficult to restore it. Remember the safety rules when working with a high-speed tool. Your car must have a protective cover that protects against splinters and sparks. Do not work with wheels with high wear, this can lead to undesirable consequences. Basically, that’s all there is to know about grinding wheels.