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O-Ring Design Info


The ‘O’ ring, or toroidal seal, is an exceptionally versatile sealing device. Applications, ranging from garden hose couplings to aerospace or oil and gas duties, make it the world’s most popular volume-produced seal. O-rings offer many benefits to designers, engineers, maintenance staff and plant operators,

  • Suit many static and dynamic applications.
  • Are very compact and occupy little space.
  • Seal efficiently in both directions.
  • Can work between -76° to +428°F (-60° to +228°C) depending on material type.
  • Can function at temperatures down to -200°C when made of PTFE.

O-Rings are inserted into cavities defined as glands, and are typically used in one of two seal designs, axial or radial.

An O-Ring is specified by its inner diameter, its cross-section diameter, its material hardness/durometer (typically defined by the Shore A hardness), and its material composition.

In order for an O-Ring to seal against the movement of fluid, it must be compressed when seated inside the gland. A standard set of design guidelines exist to determine the proper O-Ring dimensions for radial and axial seals of a given dimension.