How to divide the mesh of the grinding wheel

The "mesh" of the grinding wheel is divided according to the particle size. 50 mesh means that there are 50 holes per inch, and 500 mesh is 500, the number of meshes.

The higher it is, the more holes, the higher the mesh number, and the smaller the particle size.

In the case of rough grinding, the grinding allowance is large, and the required surface roughness.

For larger values, coarser abrasive grains should be used. Because the abrasive grain is coarse and the pores are large, the grinding depth can be large, and the grinding wheel is not easy to clog and heat.

When fine grinding, the allowance is small, and the roughness value is low, so a finer abrasive grain can be selected. In general, the finer the abrasive grain, the better the roughness of the grinding surface.

There are three organizational states of grinding wheels: compact, medium, and loose; Subdivided into 0-14 levels, a total of 15 levels. The smaller the tissue number, the larger the proportion of abrasive grains and the tighter the grinding wheel; Conversely, the larger the tissue number, the smaller the abrasive grain ratio and the looser the grinding wheel.

The "eye" of the grinding wheel is divided according to the particle size of the grinding wheel abrasive, which refers to the size of the abrasive particles, and the particle size is divided into two categories: abrasive particles and fine powder.

Abrasives with a particle size greater than 40 m are called abrasives. Graded by the screening method, the particle size number is expressed in terms of the number of holes per inch of length on the screen through which the abrasive grain passes. For example, a grain of 60 is the size of a screen that fits through a screen with 60 holes per inch of length.

For abrasives with a particle size of less than 40 m, they are called micronized. Grading by micrometry, the particle size number is represented by w and the number following it, and the value after w represents the actual size of the powder. For example, W20 indicates that the actual size of the powder is 20 m

The "mesh" of the grinding wheel is the thickness of the grinding wheel, for example, 46, this is 46 mesh, 46 mesh is very coarse, the larger the value, the finer the mesh, the finest can reach the level of fine powder.

The forehead of the grinding wheel is divided according to the size of the grinding wheel abrasive grain, usually the larger the number of grinding wheels, the smaller the grinding wheel abrasive grain.

Mesh - refers to the number of grains of sand in a square, i.e. within 645 square millimeters;

##……The higher the value; The finer the particle size; The finer the grinding.

The value is small - it is considered coarse grinding, and the chips are fast!

The grinding wheel is only one of the cutting discs, of course, the grinding wheel also includes the cutting disc, the grinding disc, etc., so the difference between the grinding wheel and the cutting disc is itself a pseudo problem.

Fig. 1 shows the resin grinding wheel cutting disc, which mainly cuts metal, glass, and magnetic core.

Fig. 2 is a grinding grinding wheel, which is mainly used for grinding and polishing, ships, aerospace, power plants, and hardware and building materials.

Taking the above two pictures as an example, the cutting disc (above) is mainly used to cut all kinds of metals, ceramics, glass, and special materials.

The grinding wheel (below) is mainly for grinding and cutting, mainly for ships, aerospace, power plants, hardware and building materials.

1. Grinding wheel is the most important type of grinding tool in grinding processing.

2. The grinding wheel is a porous body made by adding a binder to the abrasive, pressing the blank, drying and roasting. Due to the different abrasives, binders and manufacturing processes, the characteristics of grinding wheels vary greatly, which has a significant impact on the machining quality, productivity and economy of grinding.

3. The characteristics of the grinding wheel are mainly determined by factors such as abrasive, particle size, bond, hardness, structure, shape and size. Punramin.

Selection rules for grinding wheels:

If the target wheel is a harder material, you can choose a loose density or a softer grinding wheel.

When working with softer materials, you can choose a wheel with a higher relative density or harder.

Hard and brittle with diamond, such as: Zhongjing glass, ceramic, cemented carbide, etc.

Hard and tough with CBN, such as ferrous metal.

Types of grinding wheels:

According to the abrasives used, it can be divided into ordinary abrasives (corundum, silicon carbide, etc.), grinding wheels and natural abrasives, superhard abrasives and (diamond and cubic grinding wheels?). boron nitride, etc.) grinding wheels. Be cautious.

According to the shape, it can be divided into flat grinding wheel, beveled grinding wheel, cylindrical grinding wheel, cup grinding wheel, disc grinding wheel, etc.

According to the binder, it can be divided into ceramic grinding wheel, resin grinding wheel, rubber grinding wheel, metal grinding wheel, etc.

The characteristic parameters of the grinding wheel mainly include abrasive, viscosity, hardness, binder, shape, size, etc.

Sand preparation coarse wheels and gear blades are two different tools, and their main differences are as follows:

1.Different uses: Grinding wheel blades are mainly used to grind and cut hard materials such as metal, stone, ceramics, etc., while gear blades are used to transmit power and rotational speed, and are usually used in transmission systems in mechanical equipment.

2.The structure is different: the grinding wheel is usually composed of sand grains, which are used to grind and cut the surface of the material, and adhesive, which is used to hold the sand grains. The gear blade is composed of the gear tooth surface and the wheel hub, which is the key component used to transmit power and speed.

3.The raw materials are different: hard abrasives such as alumina and silicon carbide are usually used as sand grains, and adhesives are made of resin, rubber and other materials. The gear blades are stupid and rough, and are often made of metal materials such as steel.

4.The principle of operation is different: the grinding wheel blade grinds and cuts the material by rubbing and cutting back and forth on the surface of the material. The gear blades, on the other hand, transmit power and speed through the meshing of the tooth surfaces of the gears.

To sum up, grinding wheel and gear disc are two different tools with different uses, structures, raw materials and working belt stabilization.

Selection of particle size When grinding with a coarse-grained grinding wheel, the production efficiency is high, but the surface of the grinding workpiece is rough; When grinding with a fine-grained grinding wheel, the surface roughness of the grinding workpiece is better, but the productivity is lower. On the premise of meeting the roughness requirements, the grinding wheel with coarse grain size should be selected as much as possible to ensure high grinding efficiency. Generally, coarse-grained grinding wheels are used for coarse grinding, and fine-grained grinding wheels are used for fine grinding.

The general range of use of abrasive particle size 36 General flat grinding, cylindrical grinding and centerless grinding 60 Fine grinding and tool sharpening Laizhou Weiyi test equipment manufacturing****.

1.Selection of abrasive types.

When grinding stainless steel, white corundum (wa) is generally more suitable. Because white fused alumina has good machinability and self-sharpening properties.

Single-crystal corundum (sa) each particle is basically a single crystal of spherical polyhedron, there are no cracks and residual stresses formed due to mechanical crushing, there is less sudden breakage of a single abrasive grain in grinding, and there is a good hardness and toughness matching, so the grinding performance is good. When grinding stainless steel, there are fewer grinding scratches, especially the large hole single crystal corundum grinding wheel, which has a good application effect in production.

When grinding precipitation hardened stainless steel, it is better to use microcrystalline corundum (MA) grinding wheel, which has the advantages of high toughness, high cutting performance and high service life. Self-sharpening is cracked along the crevices of microcrystalline corundum, and there will be no rapid or whole abrasive grain shedding, which is conducive to reducing grinding heat and reducing grinding wheel clogging.

2.Selection of abrasive grain size.

The size of the abrasive grain size has a direct impact on the roughness of the machined surface. Due to the toughness of stainless steel materials, the grinding chips are easy to adhere and block, if the fine-grained grinding wheel is used, the abrasive loses its cutting effect due to the blockage of the grinding wheel, and it is easy to make the surface of the workpiece brushed. Production practice proves that the coarse grinding should use F36, F46 grit, and the fine grinding can use F60 grit, in order to adapt to the coarse grinding, fine grinding, often use F46, F60 grit grinding wheels.

3.Selection of binder.

Grinding wheels for cutting, grooving and centerless grinding of stainless steel materials can be made with resin bonds, which are strong, elastic, not afraid of impact, porosity, and can be used for high circumferential speeds. However, the hardness of the resin binder grinding wheel is low and it is afraid of alkaline solution. If the grinding wheel is placed in paraffin wax for a period of time before use, it can prevent the influence of alkaline solution.

4.Selection of grinding wheel hardness.

When grinding stainless steel, it is advisable to choose a grinding wheel with low hardness, which has good self-sharpening performance. However, when the hardness of the grinding wheel is too low, the abrasive particles are not firmly bonded and fall off before they are dulled, which greatly shortens the service life of the grinding wheel.

The production time proves that J3 N2 is more suitable for grinding the hardness of the grinding wheel of stainless steel, and K1 and L2 are the most commonly used. The hardness of the internal grinding wheel with microcrystalline corundum as abrasive is better than J3.

5.Selection of grinding wheel organization.

When grinding stainless steel materials, it is easy to clog the grinding wheel, so it is generally more appropriate to choose the F5 and F8 grinding wheel structure. When the workpiece material is the same, the grinding depth is large and the contact area is large, and the grinding wheel with loose structure should be selected. When the requirements for profile grinding or surface roughness are high, a grinding wheel with a tighter structure should be selected.

For example, when grinding high-strength precipitation hardened stainless steel materials, it is more appropriate to choose F6 and F7 structures.

It has to do with materials and machines!

According to the abrasives used, it can be divided into ordinary abrasives (corundum and silicon carbide, etc.), sand plum sprockets and natural abrasives, superhard abrasives and (diamond and cubic grinding wheels, boron nitride, etc.) grinding wheels;

According to the shape, it can be divided into flat grinding wheel, beveled grinding wheel, cylindrical grinding wheel, cup Narangsun grinding wheel, disc grinding wheel, etc.; According to the binder, it can be divided into ceramic grinding wheel, resin grinding wheel, rubber grinding wheel, metal grinding wheel, etc. The characteristics of the grinding wheel mainly include abrasive, viscosity, hardness, bond, shape, size, etc.