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  • All O-Rings. Buna-N, FKM, Silicone, Fluorosilicone, polyurethane

We make getting O-Rings easy! Millions of AS568 O-Rings, Metric O-Rings and Hydraulic Seals in Stock.

The O-Ring is one of the most basic and functional seals ever made and is the backbone to all the hydraulic and sealing applications in the world. An O-Ring is a solid-rubber seal shaped like a dough nut or torus. When compressed between mating surfaces, an O-Ring blocks the passage of liquids or gases. O-Rings are available in a wide range of standard and non-standard sizes that are suitable for nearly all sealing applications.

Customers of The O-Ring Store LLC, Concerning the World Wide Shortage of O-Rings:

We have dramatically increased our core inventory of O-Rings over the last year and it is currently available online on a first come first serve basis. ACH or Wire Transfer available to pay for larger orders. O-Ring and Seal production times, shipping lead times and prices are increasing every day. Domestic manufacturing is currently running ~8-12 weeks and international lead times are ~25-52 weeks to ship.

On August the 2nd the Vietnamese government ordered one or our principal manufacturing partners to close completely per Directive No. 16/CT-TTg in response to increased Covid-19 cases. The plant had previously been limited to 25% of their workforce per the directive. The mandate issued on the 2nd was set to end on August 31st; however, it has now been extended to Mid-October. Note the location of our plant is in an industrial district near Ho Chi Minh City, which is the epicenter of this resurgence. The reasons are not only the problem of Delta pandemic but also short of materials. We are badly short of NBR, silicone, HNBR, Vamac/AEM, EPDM and Viton/FKM and facing another wave of price increasing from material suppliers. The lead times for new POs could be 25-52 weeks. If there are urgent items, please contact us and we will do our best to fulfill the request.

Our basic stock compound list includes over 30 o-ring compounds making us one of the most diverse O-Ring Supplier in the Global O-Ring market. Whether you need specialized O-Ring seals or off-the-shelf standard O-Rings, we have them all at great prices. Consider us as your source for specialty polymers, high-temperature performance, and chemical resistant O-Ring and seal application requirements.

Required O-Ring Information: Sizing Must Use This Formula: 2(CS) + ID = OD

  • AS568 # or O-Ring Size (inch or metric) - Cross Section ( thickness ) X Inside Diameter - 2(CS) + ID = OD
  • Temperature Requirements
  • Compound or Material Being Sealed
  • Operating Pressure - Durometer Rating
  • Static or Dynamic O-Ring Application
  • And of Course Quantity Required (Non-Stock O-Rings may require a minimum)

With this o-ring information we can assist you in finding an o-ring seal that matches your needs, via live online chat. An additional consideration is compliance with use standards and specification such as have be established by the military, drinking water, food processing, aerospace, pharmaceutical, or your specific o-rings.

Complete listings to All O-Rings and High Performance Seals at great prices. We make getting o-rings easy!

Order O-Rings Online - Quick and Easy Since 2007 from The O-Ring Store LLC

An O-ring is a solid-rubber seal shaped like a dough nut or torus. When compressed between mating surfaces, an O-ring blocks the passage of liquids or gases. O-rings are available in a wide range of standard and non-standard sizes that are suitable for nearly all sealing applications. Two dimensions describe the size of an O-ring: its inside diameter (ID) and its cross-sectional diameter (CS).

The standard sizes used by major O-ring manufacturers are defined by Aerospace Standard AS568A, Aerospace Size Standard for O-rings. That document, published by the Society of Automotive Engineers (SAE), lists the sizes of O-rings in six series or groups in both inches and millimeters. The first five series are based on cross-sectional diameter, the sixth series includes 20 sizes for boss seals:

  • 0 series, -000 Series - 1/16" CS - 0.070" CS
  • 1 series, -100 Series - 3/32" CS - 0.103" CS
  • 2 series, -200 Series - 1/8" CS - 0.139" CS
  • 3 series, -300 Series - 3/16" CS - 0.210" CS
  • 4 series. -400 Series -1/4" CS - 0.275" CS
  • 9 series, -900 Series includes 20 sizes for Boss SAE Straight Thread O-Ring Seals

Our basic stock compound list includes over 30 o-ring compounds, with over 1,000 custom compounds available makes us one of the most diverse O-Ring Suppplier in the Global O-Ring market.

We supply O-Rings and seals in any size, material, durometer, color, and specialty performance.

Buna-N Nitrile O-Rings (NBR)

Buna-N O-Rings / Nitrile O-Rings / NBR: Buna-N O-Rings are the most widely used o-ring material in the world because of low cost, good mechanical performance with resistance to water, most basic oils, lubricants and some fuels, many pneumatic, hydraulic systems, propane, natural gas and the default choice for basic applications. Buna-N o-rings are not recommended for exposure to sunlight, UV light, ozone and general outdoor weathering or hash chemicals, acids, keytones and many others.
Lowest cost highest inventory general purpose commodity NBR compound. Compare to Parker N1470-70 and N0674-70 and Parco 4200-70 and 4900-70.

Applications: General purpose sealing, Air Tools, Hydraulic fluids, Petroleum based oils, fuels, L.P. gases, Cold Water, Silicone greases and oils, Di-ester base lubricants (MIL-L-7808), Ethylene glycol base fluids (Hydrolubes) and Hydraulic Fluids and in static and dynamic applications.
Avoid: Brake fluids, ozone and UV light
Operating temperature: -40° to +250F°

EPDM O-Rings (EPR, EPM) Ethylene Propylene Diene Monomer

Ethylene-Propylene / EPDM O-Rings: Ethylene propylene rubber is an elastomer prepared from ethylene and propylene monomers (ethylene propylene copolymer). Our stock O-Ring compounds are made with an amount of a third (diene) monomer (ethylene propylene diene terpolymers). Ethylenepropylene-diene rubber (EPDM) produced using a third monomer and is particularly useful when sealing phosphate-ester hydraulic fluids and in brake systems that use fluids having a glycol base. EPDM has outstanding resistance to heat, water and steam, alkali, mild acidic and oxygenated solvents, ozone, and sunlight; 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.

Applications: Cold and Hot Water, Steam up to 300°F (149°C), Various Water / Municipalities Applications, Household Appliances, Glycol based brake fluids up to 300°F (149°C), Many organic and inorganic acid, Cleaning agents, soda alkali, potassium alkali, Phosphate-ester based hydraulic fluids (HFD-R), Silicone Oil, Silicone Grease, Many polar solvents (alcohols, ketones, esters), Ozone resistant, aging resistant, weather resistant, Outdoor Applications and Electrical Insulators..
Avoid: Mineral oil products (oils, greases and fuels), Solvents, Aromatic Hydrocarbons, Liquefied Petroleum Gas (LPG), Lubricating Oils, Petroleum Base Gasoline
Operating temperature: -65° to +300F°
Use Only O-Ring Silicone Lubricating Grease 3oz Tube on EPDM

FEPM Aflas® O-Rings (Tetrafluoroethylene Propylene, FEPM)

Aflas® (Asahi Glass Co., Ltd.) Excellent resistance to a wide variety of aggressive chemicals. Aflas is known for its use in oil field applications and its electrical resistance properties. This elastomer is a copolymer of tetrafluoroethylene (TFE) and propylene. Its chemical resistance is excellent across a wide range of aggressive media. 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).
Operating temperature: -25° to +450F°

Highly Saturated Nitrile O-Rings (HSN, HNBR)

Hydrogenated Nitrile Butadiene Rubber (HNBR) has 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. Obtained by hydrogenerating the nitrile copolymer, HNBR fills the gap left by NBR and FKM elastomers when high temperature conditions require high tensile strength while maintaining excellent resistance to motor oil, ATF, sour gas, amine/oil mixtures, oxidized fuels and lubricating oils. Green HSN is commonly used in refrigerant R134a applications.
Operating temperature: -40° to +300F°

 FFKM Perfluoroelastomer Simriz® O-Rings

High-Performance Materials For Extreme Requirements, Simriz® Perfluoroelastomer compounds provide reliable sealing in a wide range of applications including; automotive, chemical processing, petroleum refining, semiconductor, aerospace, medical, pharmaceutical, food and drug processing, and etc.

  • General Purpose Perfluoroelastomer (FFKM) O-Rings for Basic Applications
  • Simriz® perfluoroelastomers demonstrate a wide range of temperature stability
  • Fully fluorinated monomers in Simriz® compounds provide superior protection against chemical attack
  • Simriz® possesses the resilience of an elastomer with chemical resistance approaching that of PTFE
  • Simriz® O-rings and molded shapes are available in many different Simriz compounds

Perfluoroelastomers contain an even higher amount of fluorine than FKM. They have improved resistance to high temperatures and chemicals and even withstand environments where Oxygen-Plasma are present for many hours. Certain grades have a maximum continuous service temperature of 610°F (320°C). They are commonly used to make O-rings that are used in applications that involve contact with hydrocarbons or highly corrosive fluids, or when a wide range of temperatures is encountered. We provide Simriz® O-Rings from Freudenberg (Simrit) do to the unique durability of the product and the genuine care the people from Freudenberg have given us and the users of our O-Rings. Others are commonly referred to as Kalrez® O-Rings (DuPont Dow), Chemraz® O-Rings (Greene, Tweed & Co.), Isolast® O-Rings (Trelleborg Sealing Solutions), and lesser quality brands such as Perlast (Precision Polymer Engineering), GPlast (Gapi) and Markez® (Marco).
Operating temperature: See Below

Fluoroelastomer (FPM, FKM, Viton®) O-Rings

Fluorocarbon FKM & Viton® O-Rings: Chemical resistant Fluorocarbon FKM O-Rings exhibit exceptional resistance to chemicals, oils, temperature extremes, low compression set, low gas permeability and excellent aging characteristics. It has a good resistance to ozone, high temperatures, oxygen, mineral oil, synthetic hydraulic fluids, fuels, aromatics and many organic solvents and chemicals.

Applications include: Hydraulic Oil, Petroleum Base, Silicone oil and grease, Mineral and vegetable oil and grease, Aliphatic hydrocarbons (fuel, butane, propane, natural gas), Aromatic hydrocarbons (benzene, toluene), Chlorinated hydrocarbons (trichlorethylene and carbon tetrachloride), Chlorine Water, Gasoline, Fuels, Liquefied Petroleum Gas (LPG), Natural Gas, Propane, Diesel Oil, High vacuum, ozone and weather.
Avoid: Ketones, hot water, steam, Brake Fluid, alkalis, and Skydrol® fluids, Ammonia gas, amines, alkalis,  Skydrol 500,  Methyl Ethyl Ketone (MEK),  Low molecular organic acids (formic and acetic acids)
Designed to meet or exceed the properties of these popular FKM Compounds: V747-75, V700-75, 19357, V14-75, 9009-75, F13664, 514AD and 9500-75
Operating temperature: -20° to +400F°

 Fluorosilicone O-Rings - Aerospace & Automotive Applications (FVMQ)

Fluorosilicone O-Rings / FVMQ: Fluorosilicone 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.
Operating temperature: -76° to +392F° (-60° to +200C°)

Neoprene O-Rings (CR, Chloroprene)

Neoprene® O-Rings / CR: Neoprene 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®.

Applications include: CR is resistant to refrigerants, ammonia, Freon® ( R12, R13, R21, R22, R113, R114, R115, R134A), silicone oils, water, ozone, vegetable oils, alcohols, and low-pressure oxygen.
Avoid: very low resistance to mineral oils
Operating temperature: -40° to +225F°

PTFE Polytetrafluoroethylene (AKA Teflon® O-Rings)

Polytetrafluoroethylene (PTFE) O-rings: Temperature & Chemical Resistant PTFE is a popular O-Ring material which is White in color. The PTFE O-Rings for use in applications which require a chemically resistant and non-compressible material. PTFE is the chemically inert of the O-ring materials. It is resistant to most chemicals including acids, bases, oils, steam and other chemicals. It is also very tough and abrasive resistant. However the material is not easily compressed, and therefore may not seal as easily as some of the other polymers. Its outstanding tear resistance and abrasive resistance result in its slippery surface properties that make it advantageous for use in seals in moving systems such as mass spectrometer probes and valves.
Operating temperature: -100° to +500F°

Silicone O-Rings FDA (VMQ)

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.
Operating temperature: -75° to +400F°

Urethane Cast Disogrin O-Rings (Polyurethane) High Performance

The strongest O-Ring material making it a popular choice in wear applications where abrasives, high pressure, and movement are present. Manufactured by the top polyurethane seal and component producers, with strong materials and extensive product expertise. TODI Polyurethane is the material of choice to create longevity in products due to its resistance to abrasion and performance in punishing environments. Typically called out as "cast" urethane O-rings, these parts perform well in quick disconnects, high pressure hydraulic and water applications and in nail or riveting equipment. Particularly recommended for hydraulic systems where high pressures, shock loads, wide metal tolerances, or abrasive contamination is anticipated.  Not recommenced for acids, ketones, and chlorinated hydrocarbons.  Some urethanes are also sensitive to water and humidity.
Operating temperature: -115° to +250F°

Urethane O-Rings EU (Polyurethane)

General Purpose EU Polyurethane rubber is notable for its combination of hardness with elasticity, outstanding abrasion resistance and tear strength. Elastomeric urethane rubber, not to be confused with thermoplastic polyurethane, is often referred to as the "millable gum" urethane. Polyurethane is a moderately expensive material whose use is usually limited to applications that require its outstanding physical properties. Common end use applications are industrial seals, Air Guns, Paintball Markers, pneumatic applications, and other high dynamic applications.
Operating temperature: -30° to +180°F

Teflon® PTFE Encapsulated O-Rings FKM or Silicone

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.
Operating temperature: FKM -10° to +300°F - Silicone -80° to +500°F

Viton® Extreme Chemical Resistant ETP O-Rings

Super Chemically Resistant Viton® ETP O-Rings - Extreme Chemical Resistant Fluorocarbon provides significantly improved chemical resistance compared to standard FKM A type fluoroelastomers. CV75 Viton® Extreme is so chemically resistant it can be considered a cost-effective to FFKM Perfluoroelastomer alternative for some applications with temperatures below 400°F. CV75 Viton® Extreme can also be considered as an alternative to other perfluoroelastomers like Chemraz®, Kalrez®, Perlast®, Isolast®, Parofluor®, and most certainly Markez®.

CV75 Viton® Extreme is a premium peroxide cured fluoroelastomer that exhibits the broadest fluids resistance of any FKM fluoroelastomer. It is resistant to aliphatic/aromatic hydrocarbons, polar fluids, hydraulic fluids, fuels/alcohols, strong bases, organic amines, and high pH fluids.
Operating Temperature: -8 to 482°F