1) The initial grinding stage. When the grinding wheel starts to contact the workpiece, the actual grinding depth is smaller than the radial feed amount due to the elasticity of the workpiece, fixture, grinding wheel, and machine tool system (in quantitative radial feed grinding).
2) Stable phase. When the system's elastic deformation reaches a certain level, when it continues to feed, its actual grinding thickness is basically equal to the radial feed.
3) The attrition stage. After grinding away the main machining allowance, you can reduce the radial feed or no feed at all, and re-grind several times. At this time, due to the small cutting force and the small elastic deformation of the system, the actual grinding thickness is greater than the radial feed . As the workpiece is ground layer after layer, the actual grinding depth approaches zero, and the grinding sparks gradually disappear. The grinding stage is mainly to improve the grinding accuracy and surface quality.