The first stage is the shedding cutting stage. In this constant-pressure honing, due to the rough hole wall at the beginning, the contact area between the whetstone and the hole wall is small, the contact pressure is large, and the protruding part of the hole wall is quickly ground away. However, due to the high contact pressure on the surface of the whetstone and the wear of the whetstone binder by the cutting chips, the bonding strength between the abrasive particles and the binder is reduced. Therefore, some abrasive particles fall off by themselves under the action of the cutting pressure, and the whetstone surface is exposed. Abrasive particles, this is the self-sharpening of whetstone. The second stage is the crushing and cutting stage. With the progress of honing, the surface of the hole becomes more and more polished, and the contact area with the oilstone becomes larger and larger, the contact pressure per unit area decreases, and the cutting efficiency decreases. At the same time, the cut chips are small and thin, and the wear of the binder by these chips is also very small. Therefore, the whetstone abrasive particles fall off very little. At this time, the grinding is not based on new abrasive particles, but is cut by the tip of the abrasive particles. Therefore, the tip of the abrasive particles is heavily loaded, and the abrasive particles are easily broken and shattered to form new cutting edges. The third stage is the blockage cutting stage. When honing continues, the contact area between the oilstone and the hole surface becomes larger and larger, and the extremely fine chips accumulate between the oilstone and the hole wall and are not easily removed, causing the oilstone to block and become very smooth. Therefore, the cutting ability of oilstone is extremely low, which is equivalent to polishing. If you continue to honing, the oilstone will become severely clogged and cause cohesive clogging. The oilstone will completely lose its cutting ability and generate severe heat, which will affect the accuracy and surface roughness of the holes. The honing should be ended as soon as possible.