In the hardness representation of resinoid grinding wheels, 26 English letters represent different hardness grades, and the hardness gradually increases from A to Z.
A - H: belongs to the softer hardness range.
A is the softest grade, and the abrasive grains are easy to fall off. It is suitable for grinding softer materials, such as non-ferrous metals such as aluminum and copper, and some non-metallic materials. As the letters move backward, the hardness gradually increases. H is relatively harder than A, and can be used for grinding some soft materials with higher surface roughness requirements.
I - P: It is a medium hardness range.
Resinoid grinding wheels in this range are widely used. For example, I and J grade grinding wheels can be used for semi-finishing and finishing grinding of ordinary steel parts; K and L grades are suitable for grinding alloy steel and other materials with medium hardness; M - P grades have higher hardness and are often used for grinding high-hardness alloy steel, tool steel, etc., which can maintain a certain grinding efficiency while obtaining better processing surface quality.
Q - Z: represents the hard hardness range.
Q and R grade resinoid grinding wheels are suitable for grinding high-hardness materials such as hardened steel and cemented carbide, but attention should be paid to the feed rate and grinding speed during grinding to avoid excessive wear of the grinding wheel or burning of the workpiece; S - Z are grades with very high hardness, generally used for grinding special high-hardness materials or occasions with extremely high requirements for grinding wheel hardness, such as grinding of ceramic materials.
Resinoid grinding wheels produced by different manufacturers may have certain differences in actual hardness even if they have the same hardness grade. When choosing, you need to refer to the manufacturer's product manual and actual use experience.
Southeast Asian products generally use O-Q to indicate the hardness of resinoid grinding wheels, while European and American products generally use S-V to indicate the hardness of grinding wheels. In fact, Asian products are generally made relatively softer, with low binder and molding density. European products are generally made harder, with relatively large binder and molding density.
The hardness of resinoid grinding wheels can be seen from the representation of the product. However, many manufacturers are still unable to fully establish the intrinsic connection between the hardness of grinding wheels and terminal uses. According to the use effect of the product, the formula and process can be fixed to provide solutions for a certain industry. Test the corresponding hardness and mark the appropriate hardness letter, which is a complete closed loop.
