Sizes

		2-XXX		3-XXX		5-XXX			8-XXX

 
An o-ring is a torus or a doughnut shaped object, generally made from an elastomer. They are designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface. An O-Ring is a means of closing off a passageway and preventing an unwanted loss or transfer of fluid. The O-Ring seal consists of two elements, the O-Ring itself and a properly designed gland to contain the elastomeric material.

O-rings are one of the most common seals used in machine design because they are inexpensive and easy to make, reliable, and have simple mounting requirements. They can seal tens of MPA (thousands of psi) pressure.

Static and Dynamic O-Ring Sealing Applications
Static Sealing – in which there is little or no relative motion between the mating surfaces: and
Dynamic Sealing – which must function between surfaces with definite relative motion, such as seal on the piston or hydraulic cylinder. Of the two types, dynamic sealing is the more difficult and requires more critical design work and materials selection.
O-ring selection is based on chemical compatibility, application temperature, sealing pressure, lubrication requirements, quality, quantity and cost.

Standard O-rings are made from a variety of Parker-developed rubber compounds and compression molded into the shape of an O-Ring. Base polymers include polyacrylate (ACM), ethylene acrylate (AEM), butyl rubber (Isoprene, IIR), polychloroprene rubber (Neoprene), ethylene propylene rubber (EPM, EPDM), fluorosilicone, acrylonitriles-butadiene (Nitrile, NBR), hydrogenated nitrile (HNBR), polyurethane (AU), silicone, fluorocarbon (Viton, FKM), tetrafluoroethylene propylene (Aflas), high performance fluoroelastomers (Hifluor), and perfluorinated elastomer (Parofluor and Parofluor ULTRA).

Industry standard O-Ring sizes in accordance with AS 568 dimensions are available or custom O-Rings of practically any dimension can be made to fit an application. Miniature o-rings, large special o-rings, continuously molded and spliced cord are just a few examples of the custom o-ring possibilities.