Ring-shaped gaskets are used primarily for sealing. O rings are applied in two general design applications static non moving & dynamic moving . Static applications may range from vacuum to over 60000psi for sealing flanges and o ring grooves. Other details o rings manufactured at sam engineers confirms to almost all the standards as mentioned below, British standard bs1806 specification for dimensions of toroidal sealing rings. Us sae as568 aerospace size standard for o, Rings and the equivalent local standard. Australian standard as2842, 1986 fluid power o, Rings and housings. And the commonly used metric standards are british standard bs4518 specification for metric dimensions of toroidal sealing rings. Japanese standards association jis b 2401 o, Rings and there are similar swedish and french standards publications. German and international standards publications. O rings provided in multiple materials are nitrile 70 & 90 durometer viton 75 & 90 durometer neoprene epdm silicone fluorosilicone kalrez, Perfluoroelastomer sbr ptfe fep encapsulated viton & silicone