The O-ring is suitable for installation in a variety of mechanical equipment, in the specified temperature, pressure, as well as different liquid and gas media, in the static or moving state of the sealing role. In Machine tools, ships, automobiles, aerospace equipment, metallurgical machinery, chemical machinery, construction machinery, construction machinery, mining machinery, petroleum machinery, plastic machinery, agricultural machinery, as well as all kinds of instrumentation, a large number of applications of various types of sealing components. The O-ring is mainly used for static sealing and reciprocating motion sealing. When used for rotating motion seals, it is limited to low speed rotary sealing devices. O-ring is generally installed in the outer circle or inner circle on the cross section of the rectangular groove in the sealing role. O-type sealing ring in oil resistance, acid and alkali, grinding, chemical erosion and other environments continue to play a good sealing, damping effect. Therefore, the O-ring is one of the most widely used seals in hydraulic and pneumatic transmission systems.