With flat edges on all four sides, these O-rings make contact with a larger surface area than round-profile O-rings. The increased contact creates a better seal in static applications, such as hose, pipe, and faucet connections. However, these O-rings aren’t as good of a choice in dynamic applications, where the flat edges cause higher friction that leads to increased wear. Made from Buna-N, they resist tearing and stand up to hydraulic and motor oils.

With four points of contact for a strong seal, these X-profile O-rings are often used in dynamic applications, such as on pistons and rotating shafts. Also known as Quattro seals and X-rings, they resist rolling and twisting better than round- and square-profile O-rings. They also require less compression to seal, which reduces friction and extends their service life. These O-rings are made of Buna-N, which is resilient and tear resistant. They resist hydraulic and motor oil.

Choose these O-rings for their adherence to strict military standards for material and construction. Made of Buna-N, they stand up to a variety of oils and fuels as well as ammonia, ethylene glycol, and isopropyl alcohol. They’re also resilient and tear resistant. These O-rings are made in the U.S.

O-rings that meet MIL-I-45208 have undergone rigorous inspection for quality control.

O-rings that meet MIL-P-5315 are the best choice for use with hydrocarbon fuels. They’re often used in engine fuel systems in airplanes and other vehicles.

More abrasion resistant than Buna-N O-rings, these polyurethane O-rings resist mineral oil, motor oil, and ethylene glycol. They have a round profile and are suitable for a wide range of static and dynamic sealing applications. All are sized to the SAE standard AS568.

These O-rings are harder and stronger than standard polyurethane O-rings to handle high-pressure applications. They resist mineral oil, motor oil, grease, hydraulic oils, and synthetic lubricants.

A step up from Buna-N, these HNBR O-rings contain extra hydrogen to better resist chemicals, weather, and abrasion. They won’t swell from contact with grease and acid, making them a good choice in engine, hydraulic, and HVAC systems. Because they won’t deteriorate from ozone, UV, and oxidation, these O-rings are also good for outdoor use. However, they won’t withstand solvents or strong acids like Viton® fluoroelastomer O-rings do. They’re also known as hydrogenated nitrile and highly saturated nitrile O-rings.

All have shelf life, cure date, and a traceable lot number printed on the bag.

These Viton® fluoroelastomer O-rings resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. They have a round profile and are suitable for both static and dynamic sealing applications.

Inch O-rings have a dash number and are sized to the SAE standard AS568.

Made of Viton® fluoroelastomer, these O-rings won’t degrade when exposed to chemicals such as sulfuric acid, butyl alcohol, and ethylene glycol. They’re also FDA compliant for direct contact with food. Since they’re softer and easier to compress than standard Viton® O-rings, they form a better seal in low-pressure applications. They offer the same oil resistance as Buna-N O-rings and withstand high temperatures, making them ideal for food lines with hot oil. All have shelf life, a cure date, and a traceable lot number printed on the bag.

These hard O-rings offer better wear resistance than standard Viton® fluoroelastomer O-rings. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. All have a round profile and are suitable for both static and dynamic sealing applications. These O-rings are sized to the SAE standard AS568.

Also known as Quattro Seals and X-rings, these X-profile O-rings have four points of contact for a better seal in moving parts than round-profile O-rings. Since they require less compression to make a seal, they also last longer. Made of Viton® fluoroelastomer, these O-rings resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. All have shelf life, a cure date, and a traceable lot number printed on the bag.

These durable Viton® fluoroelastomer O-rings bounce back to shape after repeated compression better than other types of Viton® fluoroelastomer O-rings. They resist a wide range of chemicals, including boric acid, butyl alcohol, and ethylene glycol. These O-rings have a round profile and are suitable for both static and dynamic sealing applications. They have shelf life, cure date, and traceable lot number printed on the bag.

Inch O-rings are sized to the SAE standard AS568.

Because one black O-ring looks just like another, these Viton® fluoroelastomer O-rings are brown for easy identification. They resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol. All have a round profile and are suitable for both static and dynamic sealing applications. O-rings have shelf life, cure date, and traceable lot number printed on the bag.

Inch O-rings have a dash number and are sized to the SAE standard AS568.

Made and bagged in an ISO Class 7 clean room, these O-rings won’t shed particles. They’re made of Viton® fluoroelastomer, which resists chemicals such as benzene, butyl alcohol, and ethylene glycol. All have shelf life, a cure date, and a traceable lot number printed on the bag.

Made of Viton® fluoroelastomer, these O-rings meet MIL-R-83248 standards. They stay strong when used with chemicals such as benzene, butyl alcohol, and ethylene glycol. You’ll often find them used in aerospace fuel and hydraulic systems. All have shelf life, a cure date, and a traceable lot number printed on the bag.

Made from PTFE, these O-rings withstand extreme temperatures and harsh chemicals such as acetone, fluorinated solvents, and ethanol. They’re also rigid, which makes them more difficult to install than flexible O-rings. These O-rings are often used to seal pump shafts, mixing tanks, and other equipment that processes chemicals or pharmaceuticals. They’re also FDA compliant for direct contact with food. All have a cure date and a traceable lot number printed on the bag.

Inherently softer and more compressible than PTFE O-rings, these Kalrez 4079 O-rings have comparable chemical resistance. Use them with acetone, methyl ethyl ketone (MEK), potassium hydroxide, and most acids. They have a round profile and are suitable for a wide range of static and dynamic sealing applications.

Inch O-rings have a dash number and are sized to the SAE standard AS568.

Kalrez 6375 O-rings are preferred over Kalrez 4079 for chemical-processing environments and applications involving steam. They resist acetone, methyl ethyl ketone (MEK), potassium hydroxide, and most acids. All have a round profile and are suitable for a wide range of static and dynamic sealing applications. These O-rings are sized to the SAE standard AS568.

These fluorosilicone O-rings remain flexible at temperatures as low as -75° F. They resist ethanol, ethylene glycol, and isopropyl alcohol. All have a round profile and are suitable for a wide range of static and dynamic sealing applications. These O-rings are sized to the SAE standard AS568.

Get the same chemical and heat resistance as Kalrez 4079 without the brand name. Even at 600° F, these FFKM O-rings resist a wide range of chemicals, including acetone, methyl ethyl ketone (MEK), potassium hydroxide, and most acids. All have a cure date and a traceable lot number printed on the bag.

These silicone O-rings have a round profile and are suitable for a wide range of static sealing applications. All have a cure date and a traceable lot number printed on the bag.

Inch O-rings have a dash number. They withstand temperatures up to 400° F. USP VI Certified, they meet testing requirements for material quality.

Able to withstand temperatures up to 400° F, these silicone O-rings are softer than standard silicone O-rings for a better seal in low-pressure applications. They have a round profile and are suitable for a wide range of static and dynamic sealing applications. All are sized to the SAE standard AS568.

These EPDM O-rings resist water, steam, ethanol, and ethylene glycol. They have a round profile and are suitable for a wide range of static and dynamic sealing applications. All are sized to the SAE standard AS568.

These O-rings withstand higher temperatures than standard EPDM O-rings. They resist water, steam, ethanol, and ethylene glycol. All have a round profile and are suitable for a wide range of static and dynamic sealing applications. These O-rings have shelf life, cure date, and traceable lot number printed on the bag.

Inch O-rings have a dash number and are sized to the SAE standard AS568.

Made of FDA-compliant EPDM, these O-rings are safe for direct contact with food. They hold up to a wide range of temperatures, and they won’t degrade from steam or water. They’re strong enough for use in moving assemblies, such as food-grade pumps and beverage dispensers. All have shelf life, cure date, and a traceable lot number printed on the bag.