O-ring

O-rings are rubber seals with a circular cross section. Because their cross sections are O-shaped, they are called O-rings, also called O-rings. It first appeared in the mid-19th century, when it was used as a sealing element for steam engine cylinders.
O-rings are the most common mechanical design for sealing because they are cheap, simple to manufacture, reliable, and simple to install. O-rings withstand tens of megapascals (thousand pounds). O-rings can be used in static applications or in dynamic applications with relative motion between components, such as rotary pump shafts and hydraulic cylinder pistons.