O-rings are suitable for mounting on a wide range of mechanical equipment and function in a static or moving state at specified temperatures, pressures, and in different liquid and gaseous media. In the machine tools, ships, automobiles, aerospace equipment, metallurgical machinery, chemical machinery, engineering machinery, construction machinery, mining machinery, petroleum machinery, plastic machinery, agricultural machinery, and various types of instruments, a wide variety of sealing elements are used. O-rings are mainly used for static and reciprocating seals. For rotary motion seals, only for low speed rotary seals. O-rings are generally mounted in a groove with a rectangular cross section on the outer or inner circle to seal. O-ring seals still have good sealing and shock absorption in oil, acid, alkali, grinding and chemical corrosion. Therefore, O-rings are the most widely used seals in hydraulic and pneumatic transmission systems.