Toroidal sealing o-rings offered by spareage india are basically devices used for closing [sealing] a gap or making a joint fluid tight. These o-rings are available for hydraulic, pneumatic and rotary applications. The o-rings are normally suitable for static and slow reciprocating application. For rotary applications the o-rings may be used where peripheral speeds are exceptionally low. The o-rings can also be used in the two sealing categories, viz, static seal, where the sealing takes place between surfaces which do not move relative to one another; and dynamic seal, where sealing takes place between surfaces which have relative movement, for eg, reciprocating movement of a rod or a piston in a cylinder. The o-ring material chosen must be resilient enough to flow into any irregularities in the surface being sealed. The o-rings used for static sealing are zero leakage seals which aim at providing a complete physical barrier in a potential leakage path to which they are applied. The dynamic o-rings perform sealing by imparting a preload pressure or squeeze providing sealing, due to the interference fit in a static condition. Under fluid pressure acting on one side of the seal through the clearance gap, the o-ring section is deformed increasing the interface pressure by an equal amount to the fluid pressure.