Various components of the binder, such as clay, talc, feldspar and water glass, all have compounds that can be burned out or evaporated at high temperatures. Therefore, during the sintering of the abrasive blank at a temperature of 1250-1300 degrees, the burned out and evaporated compounds form gas in the blank. This gas tries to expand under the influence of high temperature, and thus combines into a single space. Due to the inhalation of the newly generated gas, these spaces continue to increase, compacting the sintered binder to form pores. The gas space breaks through the binder at the thinnest part of the cross section and combines with other gas spaces to form a channel, namely the pore path.