Global O-Ring and Seal

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.

SHOP FOR O-RINGS

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.

 

Durometer

 

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.

What Are O-Rings Made Of?

Also known as a toric joint, an O-ring is a gasket consisting of a circular, ring-shaped piece of material. Like other gaskets, it’s used to create a seal. When two parts are joined together, they may be fitted with an O-ring to prevent pressurized liquids or gases from leaking.

To create an effective seal, though, O-rings must be constructed of specific materials. O-rings can’t be made of just any material. If a material is weak or even too rigid, it may fail to withstand the compressive forces of pressurized liquids or gases.

Silicone Rubber

Silicone rubber is a common material used in the construction of O-rings. Silicone rubber O-rings are resistant to both cold and hot temperatures, and they also have a longer lifespan than O-rings made of other materials. Furthermore, food and beverage companies often use them because silicone is considered safe and nontoxic. With these properties, silicone rubber is a popular material for O-rings.

Neoprene

Some O-rings are made of neoprene. Also known as polychloroprene, neoprene is a type of synthetic, manmade rubber. When compared to natural rubber, neoprene offers greater protection against degradation. This means neoprene O-rings can create longer-lasting seals while requiring less-frequent replacing. Neoprene O-rings can also withstand extreme heat. Neoprene doesn’t burn until it’s exposed to heat in excess of 500 degrees Fahrenheit.

Aflas

You may come across O-rings made of Aflas. What is Aflas exactly? It’s a polymer of tetrafluoroethylene (TFE) and propylene. Jargon aside, Aflas is recognized for its superior performance when exposed to oils and other chemicals. While harsh oils and chemicals may eat away at other materials, Aflas will resist them. Therefore, Aflas O-rings are typically used for sealing applications involving oils and chemicals.

Polyurethane

Polyurethane is another common material used in the construction of O-rings. By definition, polyurethane is an organic material that’s jointed via carbamate, urethane links. Polyurethane has many properties that make it an effective choice of material for O-rings. It’s durable, elastic and resistant to moisture. With that said, it doesn’t offer the same level of protection against oils and chemicals as Aflas.

In Conclusion

While all O-rings feature the same shape, they are available in different materials. Some of them are made of silicone rubber, whereas others are made of Aflas or polyurethane. These are just a few materials used in the construction of O-rings. Others include polytetrafluoroethylene, Buna, Viton and more.

 

O-Ring Material Chart Rubber Selection Guide Quick Reference

O-Ring Material Chart - Quick Selection Guide

Compare O-Ring Material Use Compatibility Differences

O-ring material family chemical compatibility, temperature resistance, and other properties all factor in to o-ring material selection for an application. This popular o-ring material family comparison shows basic rubber material family properties and performance plastic properties. The guide includes generalized recommended o-ring mateiral uses and non-recommended uses with typical material mechanical properties. Specific material compound formulations can significantly alter the general performance properties.

Click a material family row for details and compounds

Material

Temperature Range

Relative Price

Recommended Uses

Not Recommended For

Common Industry Applications:

Mechanical Properties

FFKM

(Perfluoroelastomer, Markez®, Chemraz® / Kalrez® / Simriz®) Standard: 5°F to 550°F
Specialty: -50°F to 650°F High Cost of Maintenence or Downtime
High Temperature Resistance
O-ring Chemical Resistance
Low Out Gassing
Chlorine Wet/Dry
Petroleum Oil
Chlorinated Hydrocarbons Molten metals
Gaseous Alkali Metals
Halogenated Freons/Fluids
Uranium Hexafluoride
Oil and Gas Explosive Decompression Resistant O-rings (Norsok O-rings, NACE O-rings)
Life Science Industry Seals
Medical O-rings and Pharma Industry Seals (USP Class VI O-rings, ISO 10993 O-rings)
Food and Beverage Manufacturing O-rings (Food & Drug Administration O-rings)
Semicon O-rings (SEM O-rings, Ultra High Purity Seals, Low Outgassing Seals, Low Particulate O-rings) Good Wear Resistance
Good Compression Set Resistance
Moderate Short-Term Resilience
Good Permeation Resistance

Buna-N

(Nitrile) Order O-rings Online Standard: -35°F to 250°F
Specialty: -70°F to 275°F Silicone Greases / Oils
Water
Petroleum Oils / Fuels
Ethylene Glycol Fluids Ketones (MEK)
Halogenated Hydrocarbons
Auto / Aircraft Brake Fluids
Strong Acids
Sunlight, Ozone,  Weathering Oil and Gas Seals
Explosive Decompression Resistant O-rings (Norsok M-710 Seals, NACE TM0297 Seals)
Automotive Fuel and Oil Seals
Military Applications (MIL Spec Compliant Seals) Good Wear Resistance
Good Compression Set Resistance
Good Short-Term Resilience
Good Permeation Resistance

Viton®

(Fluorocarbon Type A) Order O-rings Online Standard: -15°F to 437°F
Specialty: -54°F to 437°F Vacuum
Most Acids / Chemicals
Halogenated Hydrocarbons
Di-Ester Lubricants
Petroleum Oils / Fuels
Silicone Oils / Greases Ketones (MEK)
Auto / Aircraft Brake Fluids
Amines (Ammonia)
Acetone, Skydrol, Ethyl Acetate
Hot Water and Steam (except specialty grades)
Low Molecular Esters and Ethers Chemical Processing Industry Seals (CPI Seals)
Aerospace Seals (SAE, AMS, MIL Compliant Seals)
Explosive Decompression (RGD) Resistant Oil and Gas Industry Seals (Norsok M-710 O-rings, NACE TM0297 O-rings)
Automotive Fuel O-rings and Oil Seals Good Wear Resistance
Excellent Compression Set Resistance
Moderate Short-Term Resilience
Excellent Permeation Resistance

Silicone

Order O-rings Online Standard: -65°F to 400°F
Specialty: -100°F to 500°F Dry Heat
Wide Temperature Range
Sunlight, Ozone,  Weathering
Odorless and Non-Toxic Ketones (MEK)
Acids
Silicone Oils
Brake Fluids Life Science Industry Seals
Drug and Pharma Industry Seals (USP Class VI O-rings, ISO 10993 O-rings)
Medical Tubing and Seals (USP Class VI Tubing, ISO 10993 Tubing)
Food and Beverage Contact Seals (FDA O-rings, NSF-51 O-rings, 3-A Sanitary O-rings)
Drinking Water Seals (NSF-61 O-rings, WRAS O-rings, KTW O-rings)
Semiconductor Equipment Seals and Wafer Manufacturing (Ultra High Purity O-rings, Low Outgassing O-rings) Poor Wear Resistance
Excellent Compression Set Resistance
Poor Short-Term Resilience
Excellent Permeation Resistance

EPDM

(Ethylene Propylene) Standard: -65°F to 300°F
Specialty: -65°F to 300°F Sunlight, Ozone,  Weathering
Hot Water and Steam
Auto / Aircraft Brake Fluids
Some Acids and Bases
Ketones and Alcohols
Plumbing Petroleum Oils
Fuels Life Science Industry O-rings
Pharma and Medical Grade O-rings (USP Class VI Seals, ISO 10993 Seals)
Food Grade O-rings (FDA Rubber Sheet, NSF-51 Seals, 3-A Sanitary Rubber)
Drinking Water O-rings (NSF-61 Compliant Gaskets, WRAS Compliant Gaskets, KTW Compliant Gaskets) Good Wear Resistance
Good Compression Set Resistance
Moderate Short-Term Resilience
Good Permeation Resistance

Material

Temperature Range

Relative Price

Recommended Uses

Not Recommended For

Common Industry Applications:

Mechanical Properties

Aflas®

(TFE/P)

Standard: 32°F to 450°F
Specialty: -15°F to 450°F Vacuum
Most Acids / Solvents
Halogenated Hydrocarbons
Di-Ester Lubricants
Petroleum Oils / Fuels
Amines (Ammonia)
Bases
Steam Ketones (MEK)
Auto / Aircraft Brake Fluids
Acetone, Skydrol, Ethyl Acetate
Low Molecular Esters and Ethers Chemical Processing Industry O-rings (CPI O-rings)
Oil and Gas Drilling O-rings (ED Resistant O-rings, Norsok M-710 Seals, NACE TM0297 Seals)
Automotive O-rings and Oil Seals Good Wear Resistance
Moderate Compression Set Resistance
Moderate Short-Term Resilience
Excellent Permeation Resistance

Neoprene®

(Chloroprene) Standard: -35°F to 250°F
Specialty: -67°F to 250°F Refrigerants (Freon)
Ammonia
Some Petroleum Oils
Dilute Acids
Silicone ester Lubricants Ketones (MEK)
Gasoline
Auto / Aircraft Brake Fluids Refrigerant System Seals (Freon O-ring Compatibility, R22 Refrigerant, R134 Refrigerant, R410A Refrigerant, Ammonia O-rings)
Good Wear Resistance
Moderate Compression Set Resistance
Moderate Short-Term Resilience
Good Permeation Resistance

Polyurethane

Standard: -30°F to 180°F
Specialty: -65°F to 250°F Drive Belts
Some Petroleum Oils
Some Hydrocarbon Fuels
Oxygen / Ozone Ketones (MEK)
Acids
Auto / Aircraft Brake Fluids
Chlorinated Hydrocarbons
Water Mechanical Seals and Assemblies
Fluid Transfer System Seals
Hydraulic System Seals and Assemblies Excellent Wear Resistance
Poor Compression Set Resistance
Excellent Short-Term Resilience

Fluorosilicone

Standard: -80°F to 350°F
Specialty: -100°F to 350°F Jet Fuel
Dry Heat
Wide Temperature Range
Some Petroleum Oils
Chlorinated Solvents Ketones (MEK)
Phosphate Esters
Some Acids
Auto / Aircraft Brake Fluids
Amines (Ammonia) Aerospace O-rings and Aerospace Rubber Sheets (SAE Compliant O-rings, AMS O-rings, MIL O-rings)
Automotive Compliant O-rings and Gaskets
Chemical Processing O-rings (CPI Gaskets) Poor Wear Resistance
Moderate Compression Set Resistance
Moderate Short-Term Resilience
Poor Permeation Resistance

Teflon® Encapsulated

Varies with O-ring Energizer Material Chemical Resistance
Heat Resistance
High Pressure Seals Hardware Requiring a Stretch Fit
Fitting Over Sharp Edges or Burrs Chemical Processing O-rings (CPI Seals)
Chemical Handling O-rings
Chemical Storage O-rings Good Wear Resistance
Good  Short-Term Resilience
Good Permeation Resistance

Teflon®

Standard: -250°F to 450°F
Specialty: -300°F to 500°F O-ring Chemical Compatibility
Fuel Resistance
Low Coefficient of Friction Hardware Requiring a Stretch Fit
Fitting Over Sharp Edges or Burrs Chemical Processing Gaskets (CPI Seals)
Chemical Handling Gaskets
Chemical Storage Gaskets Good Wear Resistance
Low Coefficient of Friction

Material

Temperature Range

Relative Price

Recommended Uses

Not Recommended For

Common Industry Applications:

Mechanical Properties

The temperature ranges presented above are approximations for dry air service only and should not be used to determine design specifications or end-use temperature limits. Actual temperature range of a compound in an end-use application is highly dependent on part type, hardware configuration, applied forces, chemical media, pressure and thermal cycling effects, and other factors. The most practical way of determining an end-use temperature range is testing in the actual application conditions. Consult a Marco Engineer for more details.

 

Selecting an O-Ring material for a specific application depends on many important criteria including:
Service Conditions (media to be sealed, temperature range, pressure/vacuum range, dynamic motion)
Design Attributes (component geometry, desired service life, installation considerations, tolerances)

This guide is intended for general reference use only.
The materials and compound numbers listed are the most commonly used.
There are numerous compound variations designed for specific applications.
For demanding applications, please provide all the details to our application engineers for a recommendation.

 

Don't see what you need?  Please contact an application engineer for assistance in selecting the compound that provides the best combination of performance and price for your specific application.