0.101" ID O-Rings | McMaster-Carr

For a better seal in low-pressure applications, such as hydraulic return lines and oil drain plugs, these O-rings are softer than standard Buna-N O-rings.

Oil-Resistant Hard Buna-N O-Rings

Harder than standard Buna-N O-rings, these 90A durometer O-rings are more durable and wear resistant.

Square-Profile Oil-Resistant Buna-N O-Rings

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.

X-Profile Oil-Resistant Buna-N O-Rings

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.

Oil-Resistant Mil. Spec. Buna-N O-Rings

Choose these O-rings for their adherence to strict military standards for material and construction.

FDA-Compliant Oil-Resistant Buna-N O-Rings

FDA compliant for direct contact with food, these Buna-N O-rings create a strong seal in food and beverage lines.

Oil-Resistant Metal- and
X-Ray-Detectable Buna-N O-Rings

If these O-rings deteriorate, they’ll be picked up by metal- and X-ray-detection systems.

Oil- and Abrasion-Resistant Polyurethane O-Rings

More abrasion resistant than Buna-N O-rings, these also resist mineral oil and motor oil.

High-Pressure Oil- and
Abrasion-Resistant Polyurethane O-Rings

These O-rings are harder and stronger than standard polyurethane O-rings to handle high-pressure applications.

Weather- and Oil-Resistant HNBR O-Rings

A step up from Buna-N, these HNBR O-rings contain extra hydrogen to better resist chemicals, weather, and abrasion.

Chemical-Resistant O-Rings

Chemical-Resistant Viton® Fluoroelastomer O-Rings

These Viton® fluoroelastomer O-rings resist a wide range of chemicals, including benzene, butyl alcohol, and ethylene glycol.

FDA-Compliant Chemical-Resistant
Soft Viton® Fluoroelastomer O-Rings

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.

Chemical-Resistant Hard Viton®
Fluoroelastomer O-Rings

These hard O-rings offer better wear resistance than standard Viton® fluoroelastomer O-rings.

Low-Outgassing Chemical-Resistant
Soft Viton® Fluoroelastomer O-Rings

Tested to meet ASTM E595, a standard used by NASA, these O-rings give off almost no volatile emissions that could damage sensitive electronics, even in a vacuum. They’re softer than standard Viton®, so they better conform to irregular surfaces.

Low-Outgassing Chemical-Resistant
Viton® Fluoroelastomer O-Rings

Tested to meet ASTM E595, a standard used by NASA, these O-rings give off almost no volatile emissions that could damage sensitive electronics, even in a vacuum.

Square-Profile Chemical-Resistant
Viton® Fluoroelastomer O-Rings

With flat edges on all four sides, these square-profile O-rings cover more surface than round-profile O-rings for a better seal in static applications, such as hose, pipe, and faucet connections.

X-Profile Chemical-Resistant
Viton® Fluoroelastomer O-Rings

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.

Chemical-Resistant Brown
Viton® Fluoroelastomer O-Rings

Because one black O-ring looks just like another, these O-rings are brown for easy identification.

Chemical-Resistant High-Purity Clean
Room Viton® Fluoroelastomer O-Rings

These are the highest purity chemical-resistant O-rings we offer. They are made and bagged in an ISO Class 7 and Fed. Spec. Class 10,000 clean room, plus they’re USP VI certified; not for use in medical applications.

Chemical-Resistant Clean Room
Viton® Fluoroelastomer O-Rings

Made and bagged in an ISO Class 7 clean room, these O-rings won’t shed particles.

Chemical-Resistant Mil. Spec.
Viton® Fluoroelastomer O-Rings

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.

Super-Resilient Chemical-Resistant
Viton® Fluoroelastomer O-Rings

Made for demanding applications, these O-rings hold up to constant motion, repeated compression, and extreme temperatures. They’re often used for centrifugal pumps and high-pressure hydraulic valves in chemical processing systems.

Steam- and Chemical-Resistant
Viton® ETP Fluoroelastomer O-Rings

Our most chemical-resistant Viton® fluoroelastomer O-rings. Made of Viton® ETP, these O-rings stay strong when used with harsh chemicals including acetone, MEK, and sodium hydroxide. They also keep their elasticity and shape under constant motion in steam and heat.

Ultra-Chemical-Resistant Rigid PTFE O-Rings

Made from PTFE, these O-rings withstand extreme temperatures and harsh chemicals such as acetone, fluorinated solvents, and ethanol.

Ultra-Chemical-Resistant
DuPont Kalrez 4079 O-Rings

Made of Kalrez 4079, these O-rings combine the chemical resistance of PTFE with the springy softness of Viton® fluoroelastomer.

Super-Resilient Ultra-Chemical-Resistant
DuPont Kalrez 7075 O-Rings

Made for demanding applications, these Kalrez 7075 O-rings hold their shape even after repeated rubbing or compression. More durable than Kalrez 4079 O-rings, they also have higher tensile strength and heat resistance.

High-Purity Ultra-Chemical-Resistant
DuPont Kalrez 6230 O-Rings

Create seals for use in semiconductor manufacturing, food processing, and other highly controlled applications. More pure than Kalrez 4079 O-rings, these Kalrez 6230 O-rings won’t leach contaminants into your line.

Chemical-Resistant Low-Temperature
Fluorosilicone O-Rings

These fluorosilicone O-rings remain flexible at temperatures as low as -75° F. They resist ethanol, ethylene glycol, and isopropyl alcohol.

Steam- and Ultra-Chemical-Resistant Aflas O-Rings

Often used in drilling systems, these Aflas O-rings hold up to petroleum fluids. They also withstand steam and chemicals such as ammonia, calcium hydroxide, and boric acid.

Chemical-Resistant Metal-Detectable
Fluoroelastomer O-Rings

If these O-rings deteriorate, they can be picked up by metal detection systems.

Ultra-Chemical-Resistant FFKM 4079 O-Rings

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.

High-Temperature O-Rings

High-Temperature Silicone O-Rings

These silicone O-rings have a round profile and are suitable for a wide range of static sealing applications.

High-Temperature Soft Silicone O-Rings

Able to withstand temperatures up to 400° F, these O-rings are softer than standard silicone O-rings for a better seal in low-pressure applications.

Square-Profile High-Temperature Silicone O-Rings

These square-profile O-rings have flat edges on all four sides, so they cover more surface than round-profile O-rings for a better seal in static applications, such as hose, pipe, and faucet connections.

High-Temperature Clean Room Silicone O-Rings

Made and bagged in an ISO Class 7 (Fed. Std. Class 10,000) clean room, these are the highest purity high-temperature O-rings we offer.

High-Temperature Metal- and
X-Ray-Detectable Silicone O-Rings

If these O-rings deteriorate and fall in your line, they’ll be caught by metal- and X-ray-detection systems.

Water- and Steam-Resistant O-Rings

Water- and Steam-Resistant EPDM O-Rings

These O-rings also resist ethanol and ethylene glycol.

Water- and Steam-Resistant
High-Temperature EPDM O-Rings

These O-rings withstand higher temperatures than standard EPDM O-rings.

FDA-Compliant Water- and
Steam-Resistant EPDM O-Rings

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.

Water- and Steam-Resistant Soft EPDM O-Rings

Soft and pliable, these O-rings create a better seal in low-pressure applications than standard EPDM O-rings. They resist water, steam, and glycol—you can also use them outdoors.

Water- and Steam-Resistant Hard EPDM O-Rings

Harder than standard EPDM O-rings, these O-rings are more resistant to abrasion and wear.

Water- and Weather-Resistant Neoprene O-Rings

Resistant to changing weather—from rainwater to sunlight—these neoprene O-rings are good for outdoor use.

About O-Rings

Oil-Resistant O-Rings

Oil-Resistant Buna-N O-Rings

Oil-Resistant Soft Buna-N O-Rings

Oil-Resistant Hard Buna-N O-Rings

Square-Profile Oil-Resistant Buna-N O-Rings

X-Profile Oil-Resistant Buna-N O-Rings

Oil-Resistant Mil. Spec. Buna-N O-Rings

FDA-Compliant Oil-Resistant Buna-N O-Rings

Oil-Resistant Metal- andX-Ray-Detectable Buna-N O-Rings

Oil- and Abrasion-Resistant Polyurethane O-Rings

High-Pressure Oil- andAbrasion-Resistant Polyurethane O-Rings

Weather- and Oil-Resistant HNBR O-Rings

Chemical-Resistant O-Rings

Chemical-Resistant Viton® Fluoroelastomer O-Rings

FDA-Compliant Chemical-ResistantSoft Viton® Fluoroelastomer O-Rings

Chemical-Resistant Hard Viton®Fluoroelastomer O-Rings

Low-Outgassing Chemical-ResistantSoft Viton® Fluoroelastomer O-Rings

Low-Outgassing Chemical-ResistantViton® Fluoroelastomer O-Rings

Square-Profile Chemical-ResistantViton® Fluoroelastomer O-Rings

X-Profile Chemical-ResistantViton® Fluoroelastomer O-Rings

Chemical-Resistant BrownViton® Fluoroelastomer O-Rings

Chemical-Resistant High-Purity CleanRoom Viton® Fluoroelastomer O-Rings

Chemical-Resistant Clean RoomViton® Fluoroelastomer O-Rings

Chemical-Resistant Mil. Spec.Viton® Fluoroelastomer O-Rings

Super-Resilient Chemical-ResistantViton® Fluoroelastomer O-Rings

Steam- and Chemical-ResistantViton® ETP Fluoroelastomer O-Rings