How to choose the right grinding wheel

grinding wheel are determined by factors such as abrasive, grain size, hardness, binder, shape and size.
Abrasive: Abrasive is the main raw material for the manufacture of grinding wheel, it is responsible for the cutting work. Therefore, the abrasive must be sharp, and have high hardness, good heat resistance and certain toughness.
Grit: Grit refers to the size of the abrasive particles. The choice of abrasive particle size is mainly related to the surface roughness and productivity. Coarser abrasive grains shall be selected for rough grinding and finer abrasive grains shall be selected for fine grinding. Generally speaking, the finer the abrasive particles, the better the grinding surface roughness.
binder: the material used to bond the abrasive in the grinding wheel is called the binder. The strength, impact resistance, heat resistance and corrosion resistance of the grinding wheel are mainly determined by the performance of the binder.
Hardness and its choice The hardness of the grinding wheel refers to the difficulty of the abrasive grains on the surface of the grinding wheel to fall off under the action of the grinding force. The hardness of the grinding wheel is soft, indicating that the abrasive grains of the grinding wheel are easy to fall off, and the hardness of the grinding wheel is hard, indicating that the abrasive grains are difficult to fall off. The hardness of the grinding wheel and the hardness of the abrasive are two different concepts. The general principle of choosing the hardness of the grinding wheel is: when processing soft metal, choose a hard grinding wheel; when processing hard metal, choose a soft grinding wheel. The former is because the abrasive wear is very slow, do not need too early from the grinding wheel; the latter is because the abrasive wear faster need to update the abrasive faster to improve self-sharpening.
When grinding, in order to ensure the grinding accuracy and roughness, a slightly harder grinding wheel should be selected. When the thermal conductivity of the workpiece material is poor and easy to produce burns and cracks (such as grinding carbide, etc.), the grinding wheel should be soft.
shape and size and its choice: according to the structure of the machine tool and the needs of grinding wheel made of various shapes and sizes. The outer diameter of the grinding wheel should be selected as large as possible to increase the peripheral speed of the grinding wheel, which is beneficial to improve the grinding productivity and surface roughness. In addition, under the condition of machine rigidity and power permission, if the material with high heat sensitivity is selected for grinding, in order to avoid the burn and crack on the surface of the workpiece, the width of the grinding wheel should be appropriately reduced.