1. The circular arc part of the track is the core part of the slide rail. The circular arc position after the first few presses is formed. When the vertical edge is rolled and folded in the subsequent pass, the formed circular arc should be effectively protected by the upper and lower rollers or horizontal wheels. Otherwise, the arc position of the material will definitely change during the stretching process, the R becomes smaller and becomes a triangle, the steel ball does not reach the bottom, and the two-point contact produces noise. Uneven stress, deformation of the slide rail, and shortened life.

 2. The principle of average force in each pass, average force on the entire line of rollers, balanced wear, and prolong the service life of the rolls.

 3. The problem of rolling stability. In production, the problem of material swaying left and right in the raceway is often encountered. In fact, the single set of rollers is asymmetrical. The force on the left is large, and the material sways to the right; the force on the right is large, and the material Swing to the left. 

4. The use of C12MoV material for the roll is to take advantage of its wear resistance, but the specific strength and hardness are contradictory. The red hardness of C12MoV must be used during heat treatment. After quenching, tempering twice or even three times can reach the hardness.