An o-ring is an "O" shaped object usually made of an elastic material known as an elastomer. O-rings serve to create a seal between two mechanical components by preventing leakage and maintaining pressure through deforming to the shape of their surrounding cavity. This simple, cost-effective device was patented by 72 year old inventor and machinist Niels Christensen in 1937. His design proved critical to the US WWII effort, spreading rapidly throughout industry.
More about O-rings:
Due to the elastic nature of their elastomeric material (called a rubber compound), o-rings exhibit the ability to be stretched larger than originally molded under stress, but return to original size once that stress is removed. Stretching an o-ring introduces stress at its contact surfaces. Fluid (gas or liquid) remains contained so long as the pressure of the fluid doesn't exceed the contact stress of the o-ring.
O-rings are usually characterized by material (or compound), durometer (Shore A hardness) and dash number. The dash number refers to a specific inner diameter (I.D.), outer diameter (O.D.), and cross section (C.S.) based on the Society of Automotive Engineers (SAE) Aerospace Size Standard for O-rings, or simply AS568 standard sizes. Other size standards do exist, including metric (in millimeters rather than inches) and Japanese Industrial Standards (JIS)
Radial O-ring Groove Design: One popular form of the o-ring is the radial or radial gland design. Variables to keep in mind are cross section (CS) diametral squeeze, gland depth (c), groove width (w),and radius (r).
Axial O-ring Groove Design: Another form of o-ring is the axial design. The variables involved are gland depth (c), groove width liquids (w) or groove width vacuum and gases (w1), and groove radius (r).
Note the difference for pressures internal and external in the two diagrams.
Please contact us at 800.323.0496 and ask for customer service, or email our O Ring specialists at inq@lutzsales.com. For fastest response, submit a web inquiry now:
