Viton (FKM) O-Rings

Viton® (FKM) O-Rings Material Description:

Viton® is the trade name of DuPont de Nemours, Inc.'s brand of fluorocarbon. Viton® o-ring compounds give excellent heat resistance and excellent compatibility across chemical and fluid exposures. "Viton®" has become the industry generic term for most FKM materials.

If specifying Viton® on a part print, understand you could be limited to a specific compound, which could increase the cost of the part and availability requested. Unless you want "Genuine Viton™", it is best not to specify and instead, lay out your physical requirements and general FKM.

What's The Difference Between Viton® & FKM O-Rings?

The main difference between Viton® & FKM o-rings is mostly in the name. All Viton® is fluorocarbon, but not all flouorocarbon is Viton®. Chemours Company is the only one who manufactures the Viton® tradename of fluorocarbon.

The material properties of both Viton® & general FKM are very similar: excellent heat resistance and chemical, oil, ozone, resistance.

Different Viton® FKM Polymers

Chemours offers over 20 different FKM polymers. These polymers differ in fluorine content, viscosity, and curing method. Curing mechanisms can help with specific properties. For example, Bisphenol-cured polymers give better compression set resistance and peroxide-cured compounds can provide chemical resistance.

Typical examples of Viton™ polymers:

Viton A-401C – Sulfur or bisphenol-cured and the cure is already incorporated into the polymer.

Viton B-600 – B type polymers have higher fluorine content than A types. Higher fluorine content typically adds more chemical resistance.

Viton GF-600S – Considered an APA polymer, this is high fluorine and peroxide-cured. F type polymers have even more fluorine content than B types.

Viton GFLT-600S – Considered for lower temperature performance, this polymer is high fluorine, low temperature and peroxide-cured.

Viton Extreme ETP-600S – A relatively new polymer that provides the highest level of fluorine and the maximum chemical resistance. Similar to Kalrez™ or FFKM polymers in specific chemical exposure applications. It is more expensive than standard compounds, but a lot cheaper than FFKM compounds.

Each FKM supplier sells a competing polymer base or has additional performing alternatives. Some are better for low temperature and some have better base resistance.

Polymer is only one component of an FKM compound. Filler and processing aids still constitute a significant portion of the rubber compound. Giving actual physical requirements will better maintain customer part requirements.

Viton (FKM) Advantages:
  • Excellent resistance to chemicals, oil, ozone and sunlight.

Can be used with:

  • Petroleum oils and fuel
  • Mineral and vegetable oil and grease
  • Silicone oils and greases
  • Hard vacuum applications
  • Solvents
  • Water or steam (up to 400°F)
Viton (FKM) Disadvantages:

Incompatible for applications that come in contact with:

  • Amines
  • Glycol based brake fluids
  • Alkalis
  • Hydrocarbons
  • Ketones
  • Low molecular weight esters and ethers
  • Formic and acetic acids

Viton® (FKM) Material Properties

Viton® (FKM) Material Temperature Range:

Heat Resistance: Up to 212°F (100°C) with shorter life @ 250°F (121°C)

Cold Flexibility: Depending on individual compound, between -30°F and -70°F (-34°C and -57°C).

Normal Recommended Temperature Range Normal recommended temperature range

Extended Temperature Range Extended Temperature Range for short term only

PDF O-Ring Temperature Range Chart

Abrasion Resistance Good
Chemical Resistance Excellent
Cold Resistance Poor/Fair
Heat Resistance Excellent
Oil Resistance Excellent
Ozone Resistance Excellent
Tensile Strength Good/Excellent
Water/Steam Resistance Fair

Material properties & Temp ranges based on Parker o-Ring Handbook (ORD 5700) recommendations.

Select a Material to Compare:

ASTM Designation
Shelf Life
25 Years
Hardness (Shore A) Range
55 - 90

Temperature ranges will apply to the majority of media for which the material is potentially recommended. With some media however, the service temperature range may be significantly different. ALWAYS TEST UNDER ACUTAL SERVICE CONDITIONS.

ESP’s shelf life recommendation is based on the ARP 5316 standard and intended to be utilized by those organizations who do not already have specific recommendations for the control of elastomeric seals. It should be noted that the packaging of the elastomeric seals prior to assembly into a product is an integral part of the controlled storage procedure. It provides a positive means of product identity from the time of manufacture, to the time of assembly.