O-Ring Elastomers

O-Ring Elastomers Stock and Special Order

Nitrile (Buna-N) 70 Durometer Standard

Buna-N O-Rings / Nitrile O-Rings / NBR: Nitrile (Buna-N) is the most widely used elastomer due to its excellent resistance to petroleum products, operating temperature range (-40°F to +257°F) and one of the best performance-to-cost values. It's an ideal material for aerospace, automotive, propane and natural gas applications.

Operating temperature: -40° to +250F°

AS-568 Buna-N O-Rings | Metric Buna-N O-Rings

Fluoroelastomer FKM Viton®

Fluorocarbon FKM O-Rings: Fluorocarbon FKM exhibits exceptional resistance to chemicals, oils, temperature extremes (-13°F to +446°F), low compression set, low gas permeability and excellent aging characteristics. Applications include: aircraft engines, automotive fuel handling systems, and chemical processing industries. FKM is also suitable for high vacuum applications. It is not recommended for exposure to ketones, alkalis, and Skydrol® fluids. Custom compounds are available with improved chemical and low temperature resistance.
AS-568 FKM O-Rings | Metric FKM O-Rings

Chloroprene (Neoprene)

Neoprene® O-Rings / CR: Neoprene (-40º to +250ºF) is reasonably priced and features good resistance to petroleum oils, ozone, sunlight and oxygen aging, relatively low compression set, good resilience and outstanding physical toughness. It is the preferred sealing material for the refrigeration industry because of its resistance to ammonia and Freon®.
AS-568 Neoprene® O-Rings


Silicone O-Rings / VMQ: In the Silicone family, you will find compounds which are superior as static seals in extreme temperature conditions. Standard compounds handle operating temperatures -85º to +400ºF. Silicone compounds are popular in food and medical applications because they are very clean and do not impart odor or taste. Special Phenyl silicones can be used down to -148°F.
AS-568 Silicone O-Rings | Metric Silicone O-Rings

Highly Saturated Nitrile (HSN, HNBR)

Better resistance to high temperatures, superior physical properties, and improved chemical resistance over traditional nitrile compounds.  It also has better resistance to ozone, sunlight, and other atmospheric conditions.  Excellent resistance to compression set.  Green HSN is used in refrigerant R134a applications.  Temperature range:  -40° to +325°F.

Ethylene Propylene (EPR, EPDM, EPM)

Ethylene-Propylene / EPDM O-Rings: EPDM has outstanding resistance to heat, water and steam, alkali, mild acidic and oxygenated solvents, ozone, and sunlight (-40ºF to +275ºF); but it is not recommended for gasoline, petroleum oil and grease, and hydrocarbon environments. This popular rubber compound is usually the first choice for low torque drive belt applications.
AS-568 EPDM O-Rings | Metric EPDM O-Rings

PTFE [TFE, Teflon® (E.I. duPont)]

White thermoplastic fluoroethylene resin offers a combination of qualities not found in any other material - chemical inertness, heat resistance, low friction, dialectric strength, weatherability, zero water absorption, toughness, and flexibility.  Temperature range:  -65° to +500°F.

Aflas® (Asahi Glass Co., Ltd.)

Advantageous combination of high temperature, chemical, and electrical resistance properties.  Recommended for oils and lubricants, hydraulic and brake fluids, transmission and power steering fluids, sour oil and gas (H2S), amine corrosion inhibitors, ozone, steam, acids, bases, alcohols, and a variety of other chemicals.  Temperature range:  -25° to +450°F (+500°F short term).

Urethane (Polyurethane)

Resistant to petroleum oils, hydrocarbon fuels, oxygen, ozone, and weathering.  Particularly recommended for hydraulic systems where high pressures, shock loads, wide metal tolerances, or abrasive contamination is anticipated.  Not recommenced for acids, ketones, and chlorinatied hydrocarbons.  Some urethanes are also sensitive to water and humidity.  Temperature range:  -65° to +200°F.

Teflon® Encapsulated

Seamless and uniform Teflon® FEP encapsulation which completely encloses a core material of either silicone or Viton® elastomer.  Matches the chemical and temperature resistance of solid PTFE O-Rings and possesses the elasticity and recovery properties of the core elastomer which are crucial in many sealing applications.

Fluorosilicone (FVMQ)

Fluorosilicone O-Rings / FVMQ: Fluorosilicone (-75º to +400ºF) combines the good high and low temperature stability of silicone with the fuel, oil, and solvent resistance of fluorocarbons. FVMQ is unparalleled for aerospace fuel systems, auto fuel emission control systems and to meet or exceed government, military, aerospace, automotive, industrial and commercial specifications. However, due to relatively low tear strength, high friction and limited abrasion resistance of these materials, they are generally not used in dynamic applications. They are also not recommended for exposure to brake fluids, hydrazine, or ketones.
AS-568 Fluorosilicone O-Rings | Metric Fluorosilicone O-Rings

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