The O-ring is suitable for being installed on various mechanical equipment, and plays a sealing role under static or moving conditions at the specified temperature, pressure, and different liquid and gas media. Various types of sealing elements are widely used in machine tools, ships, automobiles, aerospace equipment, metallurgical machinery, chemical machinery, engineering machinery, construction machinery, mining machinery, petroleum machinery, plastic machinery, agricultural machinery, and various instruments and meters. O-ring is mainly used for static seal and reciprocating seal. When used for rotary motion seal, it is limited to low-speed rotary seal device. The O-ring is generally installed in the groove with rectangular section on the outer circle or inner circle for sealing. The O-ring seal still plays a good sealing and damping role in the environment of oil resistance, acid and alkali resistance, grinding, chemical corrosion, etc. Therefore, O-ring is the most widely used seal in hydraulic and pneumatic transmission systems.