Abrasive particle size
The particle size of the abrasive refers to the particle size of the abrasive. Abrasives can be divided into four groups according to their particle size: abrasive grains, grinding powder, micro powder and superfine powder. Among them, the particle size numbers of the two groups of abrasive grains and grinding powders are expressed by the number of meshes per inch of screen length, and the mark is to add a "#" symbol to the upper right corner of the number of particle sizes. For example, 240# means that there are 240 holes per inch of the screen length. The larger the particle size number, the finer the abrasive grains. The particle size numbers of the two groups of micropowder and superfine powder are expressed by the actual size of the particles, and the mark is to add a letter "W" in front of the particle size number. Sometimes it can be converted into a mesh number. For example, W20 means that the actual size of the abrasive particles is between 20μm and 14μm, which is the same as the mesh number 500#.
In the particle size of various abrasives, there are coarse, medium and fine particles. The medium particle is the basic particle size in the grinding powder, and it is the main factor that determines the grinding ability of the abrasive. It occupies a large proportion in the particle size composition. Practice has proved that the grinding capacity of the ground powder after centrifugal separation will be increased by 20% compared with that before the separation. Fine particles play a very small role in grinding. The particle size is not only detrimental to the quality of the grinding workpiece, but also reduces the grinding efficiency. The number of them should be minimized in the particle size composition. Therefore, in terms of the efficiency of grinding and the quality of work, the abrasive particles are required to be uniform. The abrasive grain group with a particle size of 12#~80# has a larger particle size and is not suitable for abrasive processing.
Abrasive hardness
The hardness of the abrasive refers to the ability of the abrasive surface to resist local external effects, while the hardness of the abrasive tool (such as whetstone) is the firmness of the binder bonded abrasive when subjected to external force, which is one of the basic characteristics of the abrasive. Grinding is achieved by using the difference in hardness between the abrasive and the workpiece to be researched. The higher the hardness of the abrasive, the stronger its cutting ability.
Abrasive strength
The strength of the abrasive refers to the firmness of the abrasive itself. That is, the ability to withstand external pressure without being broken when the edge of the abrasive grain is still quite sharp. Abrasives with poor strength have fast grinding particles, low cutting ability and short service life. This requires that the abrasive grains not only have high hardness, but also have sufficient strength to be able to perform grinding better.