The Highest Quality O-Rings Available When You Need Them

With one of the largest inventories of o-rings, cord stock, and related seals (square rings, x-rings, backup rings, and more) in North America, we’re committed to providing the right product at the right price to every customer. Our technical sales team is experienced and knowledgeable about o-rings and their application. Because of this, we provide customers with guidance that ensures the optimal solution.

Not sure what you need? Let us help you find the right seals for you. For more information or to request a quote on o-rings, please give us a call at 832-448-5550 or submit the Product Inquiry Form.


Global O-Ring and Seal offers the full line of AS568 Size o-rings in the following materials:

View our AS568 Size Chart for a full listing of all sizes and dimensions.

What is an O-Ring?

An o-ring is a round, mechanical gasket designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface. O-Rings are one of the most common types of seals because they’re inexpensive, reliable and have simple mounting requirements. Since they are known as one of the most important elements of machine design, o-rings may be used in static applications, where little range of motion is required. O-Rings may be used in dynamic applications, like rotating pump shafts and hydraulic cylinder positions, also (see o-ring size chart).

O-Ring Compounds

We offer many different o-ring compounds for a variety of applications. Visit our Compounds page to see a list of all our standard compounds and their properties.

O-Ring Material

Material matters. Due to this, selecting an o-ring material for a specific application is dependent on many criteria, including what’s being sealed, temperature range, pressure, dynamic or static service, desired service life, installation considerations, tolerances, and many more. General purpose compounds are used broadly, however, utilizing the exact compound consistently is equally as important. At Global O-Ring and Seal, you can be assured that all our general purpose o-rings meet the standards stated in our spec sheets. We do not mix compounds even for general purpose o-rings. To learn which o-ring materials will work best in your application, review our Material Selection Guide and Chemical Compatibility Table.


Determining durometer isn’t hard. The hardness of rubber compounds is measured by the Shore A durometer; the higher the durometer, the harder the compound. In addition, softer compounds stretch easier and seal better on rough surfaces. Harder compounds offer greater abrasion resistance and resistance to extrusion. To learn more about o-ring durometer, click here.

O-Ring Part Numbering System

Global O-Ring and Seal’s o-ring part numbers are designed to describe the material, durometer, size, and any special features. As an example, the graphic below displays the part number for an o-ring made of Nitrile, at a durometer of 70, with a 230 AS568 size, and is peroxide-cured. See the tables below for more material and special feature abbreviations.

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Suffix Symbol
Special Feature
(Blank) No Special Features
ETP Extreme Temp
HG High-Visibility Green
HY High-Visibility Yellow
LT Low-Temp
MD Metal Detectable
PC Peroxide-Cured
RGD Rapid Gas Decompression
YW Yellow


There’s more to o-rings than meets the eye. Specific color standards are routinely used to help visually identify the type of o-ring installed for certain industries. Because of this, we stock o-rings in the most common colors, materials and compounds. View our o-ring colors here.

Shelf Life

Shelf life for o-rings can vary anywhere from three years to unlimited, depending on elastomer type. More information on o-ring shelf life recommendations can be found here.

O-Ring Groove Design

Numerous factors go into the appropriate design of an o-ring gland. View our o-ring groove design guidelines here.

Metric O-Rings

Global O-Ring and Seal offers a large selection of metric o-ring sizes in various compounds. A “metric o-ring” simply means that the size of the o-ring is defined in millimeters. Learn more about metric o-rings.

Custom Molded O-Rings

Beyond our huge inventory of more than 50 million o-rings in all standard materials and sizes, if you’re looking for a custom size o-ring for any cross-sections larger than the AS568 400 Series (.275” CS) and/or an ID larger than the largest ID for that series, we’re your go-to provider. Learn more about custom molded o-rings.