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O-Rings

Standard AS568 and ISO 3601 Metric O-Rings

Standard AS568 and ISO 3601 O-Rings

Apple Rubber offers the seal industry's largest inventory of o-rings, which includes every standard AS568 and ISO 3601 size, and the following:

  • Inside Diameter from 1/32" (0.794 mm) to 26" (66.04 cm)
  • Outside Diameter from 3/32" (2.38 mm) to 26-1/2" (67.31 cm)
  • Cross Section from 1/32" (0.794 mm) to 1/4" (6.35 mm)

In addition to standard imperial and metric sizes, Apple Rubber also carries a wide variety of non-standard sizes. With over 300,000,000 o-rings in-stock, we have exactly what you are looking for and we can assure immediate delivery of any size in large or small quantities.

O-Ring Sizing Guides

Still have questions about finding a standard or non-standard o-ring size? Feel free
to either contact us with your questions or use our online o-ring size search.



Easy to Order, Fastest Delivery

When you are ready to get started, submit an online RFQ to receive a quote from our dedicated sales team within 24 hours. Most likely the size and compound you require is in our inventory of over 300 Million o-rings. You receive immediate shipments with no intermediate delays. Remember: With Apple Rubber, you buy direct.



Standard O-Ring Material Applications

We offer the following six (6) standard rubber materials in a range of durometer (Shore A) hardnesses to satisfy practically any service condition:

Viton® / FKM:  Fluorocarbon (Viton®) 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. Read More

Nitrile / 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. Special Hydrogenated Nitrile (HNBR) compounds can improve resistance to direct ozone, sunlight, and weather exposure while increasing temperature range to +300°F. Read More

Ethylene-Propylene / EPDM:  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. Read More

Fluorosilicone / FVMQ:  Fluorosilicone (-75º to +400ºF) combines the good high and low temperature stability of silicones 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. Read More

Silicone / 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. Read More

Neoprene® / 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®. Read More



Let us know if you require materials to meet the following standards; UL, MIL, AMS, ASTM, FDA 21 CFR 177.2600, USP Class VI, or ISO 10993.  We have many special compounds that can meet the specification you are looking for.

Need help choosing an o-ring material? Try our new, Interactive Material Selection Guide. For assistance with o-ring size or material selection, contact us today.

*Note: The current revision of the standard is AS568C, but it changes periodically. We highly recommend that in all cases, samples of a specific size and compound should be tested in the application before use in production.