Fluorocarbon (VITON® / FKM)

What is FKM / VITON®

FKM (also commonly known by the brand name VITON®) is a type of fluoroelastomer / fluorocarbon rubber.

Fluorocarbons are widely adopted in industry because they combine outstanding thermal, chemical, and environmental resistance with good mechanical performance — making them one of the most versatile sealing elastomers available.

Key Strengths & Performance Benefits

• High-temperature resistance — FKM is known for its ability to operate reliably at elevated temperatures.
• Chemical and fluid resistance — It resists a wide range of media including mineral oils, fuels, hydraulic fluids, many solvents, aromatics, and other aggressive chemicals.
• Low gas permeability — Compared to many elastomers, fluorocarbon has very low gas permeability, enhancing its sealing reliability especially in pressurised or gas-tight applications.
• Low compression set and durable mechanical properties — This helps maintain seal integrity over long periods and repeated use, reducing the risk of leaks or failures due to material fatigue.
• Resistance to environmental ageing — FKM resists ozone, oxygen, weathering, and UV exposure, making it suitable not only for industrial fluids but for outdoor or exposed applications too.

Because of this combination of properties, FKM is often considered a “universal” sealing material — suitable for a wide variety of high-demand environments.

Common Grades & Variants

FKM is available in a number of grades and formulations, each optimized for different operating conditions:

• Standard (Type A) — Often supplied in 75 Shore A (V75) or 90 Shore A (V90). General-purpose grade for broad applications.
• Type B — Used in chemical-process plants, power utilities, gaskets and seals.
• Type F — Designed for oxygenated automotive fuels, concentrated inorganic acids, water and steam.
• Type ETP / “Viton® Extreme” — Enhanced chemical resistance for aggressive media such as high-pH lubricants, greases, coolants and solvents; also used in oil exploration and drilling (e.g. sour well conditions).
• Low-Temperature (LT) variants — e.g., GLT, GFLT — For applications requiring improved flexibility at lower temperatures; some maintain elasticity to –40 °F (≈ –40 °C) or lower.

FKM compounds are generally marked under the industry standard designation ASTM D1418 = “FKM”.

They are also available in a variety of colours (not just standard black), including Brown, Green, Blue, Purple, White, Yellow, and Red depending on customer needs.

Typical Applications

Due to its versatility, FKM is used in many sectors and seal types, including:

• O-rings, cord seals, gaskets.
• Hydraulic seals, oil seals, bonded seals, extruded cord.
• Static and dynamic seals across automotive, aerospace, oil & gas, chemical processing, food/pharmaceutical (with FDA-approved compounds) industries.
• Fuel systems, hydraulic systems, engines, transmission systems — especially where high temperatures, fuels or aggressive chemicals are present.

The high fluorine grades (e.g. GF, Type B) perform especially well in high-octane and oxygenated fuel blends (such as ethanol/methanol-blended gasoline), where lower fluorine materials might swell or degrade.

Specialized grades such as “Metal Detectable / FDA” FKM exist for food, pharmaceutical, and hygiene-sensitive environments — reducing contamination risk and remaining compliant with regulatory standards like FDA 21 CFR 177.2600.

Why Choose FKM / VITON®

Because of its rare combination of thermal stability, chemical resistance, mechanical robustness, and environmental resistance, FKM remains among the most widely used elastomers for demanding sealing tasks.

Its broad compatibility — especially with oils, fuels, hydraulic fluids, solvents and many chemicals — makes it a go-to choice for “universal” sealing needs where durability and reliability are critical.

With its variety of grades and compound options, FKM can be tailored — whether you need general-purpose seals, low-temperature performance, FDA-grade for food/pharma, or chemical-resistant “extreme service” compounds — giving flexibility to match application demands.

Recommendations for Specifying FKM

• Choose the right grade — Standard A-type for general use; Type B/F/ETP for chemical or fuel-rich applications; LT-variants for low-temperature operation; FDA/metal-detectable for food/pharma.
• Check chemical compatibility — For aggressive media (amines, ketones, certain acids), verify with compatibility charts; where FKM is unsuitable, consider alternative elastomers.
• Consider application conditions — Take into account temperature extremes (both high and low), static vs dynamic sealing, presence of gases or solvents, contact with fuels or lubricants, and regulatory requirements.
• Request relevant data sheets — For each grade (e.g. V75, V90, ETP), obtain technical data sheets to confirm operating temperature range, hardness, fluid resistance, and mechanical properties.

FKM is not generally recommended for ketones, amines, or continuous hot water/steam unless specialist grades are used.

Please note — Fluorocarbons are not recommended for exposure to ketones, amines, low molecular weight esters and ethers, nitro hydrocarbons, hot hydrofluoric or chlorosulfonic acids, or Skydrol® fluids. They are also not recommended for situations requiring good low temperature flexibility.