Tips in Choosing the Right O-Ring Material for Fluid Sealing Applications

14 April 2020

One of the most common seals used in a lot of manufacturing industries today are O-rings. They work by sitting in between two parts or components for them to prevent the unwanted escape of liquids or gases.

A deciding factor in choosing your right O-ring is its material. Each material contains a unique set of properties that make them suitable for specific fluid sealing applications. The following are some materials used for manufacturing O-rings and several essential tips on how and when to use them.


The Alfas O-rings can work at a temperature range of -14° to +446°F, making them suitable in high-temperature environments and chemical applications. Some applications of Alfas O-ring include seals for aerospace, oil-related seals, and an industrial environment.


High fluorine grade O-rings can effectively work with methanol/ethanol-blended gasoline, while base resist grades can provide better oil protection and endure high temperatures. With these properties, fluorocarbons are deemed useful in applications with low compression and high temperatures such as aircraft engines and automotive fuel handling systems.

Nitrile or Buna-N

Nitrile O-rings are known for their tear-resistance and the ability to withstand abrasive treatments. They can be used on certain limited temperature and resistance requirements, making them great with water, petroleum oils, and several hydraulic fluids.

Perfluoroelastomer (FFKM)

Perfluoroelastomer O-rings combines the resistance of polytetrafluoroethylene with the flexibility and elasticity of fluorocarbon rubber (or FKM). This type of O-rings has terrific chemical resistance, excellent gas and liquid permeation resistance, and excellent weather and ozone resistance. They are also self-extinguishing and non-flammable, making them suitable for locations with high temperatures and paint and coating operations.


Silicone O-rings can operate within a temperature range of -85° to +400° F, making them appropriate for high-temperature seals. They can work well with water, steam, or petroleum fluids, as long as the application is static.

Natural Rubber

Natural rubber is the most commonly used material for O-rings since it has high tensile strength, high resilience, high abrasion, and high tear resistance. This material can also give excellent resistance to organic compounds like alcohols and acids. Natural rubber O-rings are used in seals of food and beverages. They are also used in non-hydraulic sealing applications.

Polytetrafluoroethylene (Teflon)

Teflon O-rings are virtually inert to almost all industrial chemicals and possess adequate toughness. They also perform well with different chemicals at high temperatures. Additionally, these rings have high endurance ratings and high resistance to ozone, making them usable for static and slow intermittent dynamic seals.


Polyurethane O-rings can withstand extended contact with carbon dioxide. They are also tough and can resist extrusion and abrasion. Some common applications for this type of rings include valves, cylinders, pneumatic systems, hydraulic fittings, fluid transfer systems, and firearms.

Knowing the properties and qualities of these O-rings can help you choose which one of them is needed for your specific application. If you have some questions about O-rings, just give us a call at Gasketech.

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