The hardness of China grinding abrasive disc refers to the resistance of the bonding agent to resist the detachment of the abrasive particles from the surface of the grinding disc under external force, or the ease with which the abrasive particles are detached from the surface of the grinding disc. Hardness can correctly reflect the grinding performance of the grinding disc and is one of the important indicators to measure the quality of the grinding disc. There are two requirements for the assessment of the hardness of China grinding abrasive disc:

A. The uniformity of the hardness of the grinding disc should meet the requirements of the standard;

B. The compliance requirement of hardness, that is, the average value of hardness should be within the allowable range specified by the standard. The proportion of unqualified hardness is also quite high. For example, the hardness of the flat grinding disc is unqualified by more than 20% of the total number of unqualified.