The ultra precision machining sequence of bearings can generally be divided into three steps: cutting, semi cutting, and finishing.

One step: cutting of bearings

When the surface of the grinding stone comes into contact with the convex peaks on the rough raceway surface, due to the small contact area, the force per unit area is relatively large. Under a certain pressure, the grinding stone is first subjected to the "reverse cutting" effect of the bearing workpiece, causing some abrasive particles on the grinding stone surface to fall off and break, exposing some new sharp abrasive particles and edges. At the same time, the surface protrusions of the bearing workpiece are subjected to rapid cutting, which removes the protrusions and grinding deterioration layer on the surface of the bearing workpiece through the action of cutting and reverse cutting. This stage is called the cutting stage, in which most of the remaining metal is removed.

Step 2: Half cutting of bearings

As the machining continues, the surface of the bearing workpiece is gradually ground flat. At this point, the contact area between the grinding stone and the workpiece surface increases, the pressure per unit area decreases, the cutting depth decreases, and the cutting ability weakens. At the same time, the pores on the surface of the grinding stone are blocked, and the grinding stone is in a semi cutting state. This stage is called the semi cutting stage of bearing finishing, during which the cutting marks on the surface of the bearing workpiece become lighter and a darker luster appears.

Step 3: Finishing stage

This is the final step of ultra precision machining of bearings. As the surface of the workpiece is gradually flattened, the contact area between the grinding stone and the workpiece surface further increases, and the surface of the grinding stone and the bearing workpiece is gradually isolated by a lubricating oil film. The pressure per unit area is very small, and the cutting effect decreases. Finally, the cutting automatically stops. This stage is called the smoothing stage. During the polishing stage, there are no cutting marks on the surface of the workpiece, and the bearings exhibit a bright finished product luster.