The service life of the Ball Screw can be classified into three categories in terms of function and performance: rolling fatigue life, abrasion life, and damage life. Generally, the rolling fatigue life is called the service life of the Ball Screw. When the Ball Screw rolls under load, the raceway surface of the screw shaft and nut and the rolling contact surface of the rolling element constantly apply load and flaking is caused by material fatigue. The rolling fatigue life is the total number of revolutions until flaking first occurs.