The hardness of the grinding wheel

The hardness of the grinding wheel refers to the resistance relative to the bond of the grinding wheel and the breakage of the abrasive particles.

The bonding hardness of the dicing sheet or polishing sheet can be adjusted by its own synthetic resin and mixed fillers. According to the DIN ISO 525 standard, the bonding hardness of cutting discs or sanding discs can be indicated by the letters in the model name. The marking range is from "A" (extremely soft) to "Z" (extremely hard), that is, the harder the binder, the lower the letter in the alphabet.

Generally, the harder the material to be processed, the softer the abrasive binder should be, so that the best cutting or polishing pad can be selected for the specific application.

If the user chooses a binder that is too hard, the blunt abrasive particles will not be separated from the carrier material during the working process; the consequence is that the abrasiveness of the abrasive disc will drop sharply. This may cause the cutting edge to overheat and cause the grinding disc to "smooth" until the cutting performance is completely lost.

If the user chooses a very soft binder, the abrasive will show higher abrasiveness, because there are always new abrasive particles used, thereby shortening the processing time. But the very soft binder will also accelerate the wear of the tool, thereby shortening the service life.