O-Rings are produced from a variety of compounds for specific applications.

Prevention of fluid loss or transfer may be obtained with an elastomeric (rubber) O-Ring by the yielding of a softer material (rubber) wholly or partially confined between two mating surfaces.

Some of the most common Elastomers used to produce O-Rings are as follows:

Chloroprene Rubber (CR)

Chloroprene was the first synthetic rubber and exhibits generally good ozone, aging and chemical resistance. It has good mechanical properties over a wide temperature range.   -40°F to +250°F.

Styrene-Butadiene (SBR)

SBR probably is better know under it's old names Buna S or GRS (government rubber styrene). SBR was first produced under government control between 1930 and 1950 as a replacement for natural rubber. The basic momomers are butadiene and styrene, with styrene content approximately 23.5%.  -70°F to 225°F.

Acrylonitrile-Butadiene (NBR)

Nitrile rubber (NBR) is the general term for acrylonitrile butadiene terpolymer. The higher the acrylonitrile content, the better the resistance to oil and fuel. At the same time, elasticity and resistance to compression set is adversely affected. NBR has good mechanical properties when compared to other elastomers and high wear resistance.   -30°F. to 250°F.

Ethylene Propylene Rubber (EPM,EPDM)

EPM is a copolymer of ethylene and propylene. Ethylene-propylene-diene rubber (EPDM) is 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.

Fluorocarbon (FKM) 

Fluorocarbon (FKM) (viton) has excellent resistance to high temperatures, ozone, oxygen, mineral oil, synthetic fluids, fuels, aromatics and many organic solvents and chemicals. -40°F to 400°F.

Silicone Rubber (Q,MQ,VMQ,PVMQ)

The term silicone covers a large group of materials in which methyl-vinyl-silicone (NMQ) is often the central ingredient. Silicone elastomers as a group have relatively low tensile strength, poor tear and wear resistance. However, they have many useful properties as well. Silicones have good heat resistance up to 450°F, good cold flexibility down to -75°F, and good ozone and weather resistance as well as good insulating and physiologically neutral properties.

O-Ring Making Kit

On the spot O-Ring making kit provides a seal in minutes.

Physical Properties of Common Elastomers

Standard O-Ring Dimensions

1/16" Cross-Section O-Ring Dimensions

3/32" Cross-Section O-Ring Dimensions

1/8"   Cross-Section O-Ring Dimensions

3/16" Cross-Section O-Ring Dimensions

1/4"   Cross-Section O-Ring Dimensions

Cord Stock Available in following diameters:

1/16"   (.070 +-.003)

3/32"   (.103 +-.003)

1/8"     (.139 +-.004)

3/16"   (.210 +-.005)

1/4"     (.275 +-.006)

5/16"   (.312 +-.010)

3/8"     (.375 +-.010)

7/16"   (.437 +-.010)

1/2"     (.500 +-.010)

5/8"     (.625 +-.015)