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Home / Materials / Specialty FKM
Material

Specialty FKM O-Rings — Application-Specific Fluoroelastomer Grades

FKM (fluoroelastomer) is FITCO's core high-performance material line, structured around application-specific grades rather than a single generic compound. Material selection is based on fluid, temperature, pressure, movement, operating cycle and regulatory requirement — not the FKM label alone.

When to Select

When Specialty FKM Should Be Selected

Select the FKM grade that matches your specific service condition: general-purpose for standard fuel/oil duty, high-fluorine for aggressive fuels, low-temperature for cold-climate or aerospace service, AED/RGD-resistant for gas decompression cycling, or food/pharma-compliant grades for regulated environments.

Advantages

Main Advantages

  • Broad resistance to fuels, mineral oils and hydrocarbon-based process fluids
  • Wide selection of application-specific sub-grades under one material family
  • Established global supply base and standard sizing across AS568/ISO 3601/BS/DIN/JIS
Limitations

Important Limitations

  • Standard-grade FKM is not suited to ketones, esters, amines or superheated steam
  • Cold-temperature performance varies significantly by grade — confirm the specific grade's low-temperature rating
  • Grade selection materially affects both performance and price — default/general-purpose grade should not be assumed suitable for demanding service
Sub-Grades

Specialty FKM Grade Options

General-Purpose FKM

Standard-duty grade for typical fuel, oil and mineral-hydraulic service.

High-Fluorine FKM

Improved resistance to aromatic fuels and oxygenated blends for aggressive fuel-system service.

Low-Temperature FKM

Extended cold-side service (GLT/GFLT-type grades) for aerospace and cold-climate applications, typically to around -40°C.

Peroxide-Cured FKM

Cure system offering improved compression set retention for select service conditions.

AED/RGD-Resistant FKM

Decompression-resistant grade for gas service — qualification is compound-specific.

Food/Pharmaceutical-Compliant FKM

FDA and USP Class VI compliant grades — compliance applies only to the specific documented compound.

FKM for Fuels & Aggressive Fluids

Grades selected for extended fuel and aggressive-fluid exposure.

FKM for Vacuum & Low-Permeation

Grades selected for vacuum service and low gas-permeation requirements.

Applications

Typical Industries

Chemical ProcessingOil & GasFuel & AutomotiveRefrigeration / Low Temperature
Media Compatibility

Suitable & Unsuitable Media

SUITABLE:
Mineral oils and fuelsHydraulic fluids (petroleum-based)Aromatic hydrocarbons (grade dependent)Most mineral acids (dilute)
UNSUITABLE / REQUIRES VERIFICATION:
Ketones and estersAminesSuperheated steamGlycol-based brake fluids
Technical Data

Hardness, Temperature & Standards

Hardness60–90 Shore A
Temperature Range-20°C to 200°C continuous, 230°C short-term (grade dependent)
Relevant Standards / CertificationsAS568, ISO 3601, BS 1806, DIN 3771, JIS B2401; ASTM D1418
Comparison

Specialty FKM vs. Alternative Materials

FKM is the default high-performance elastomer for hydrocarbon and fuel-based service. Where the fluid list includes ketones, amines or strong acids/bases, FEPM or FFKM should be evaluated instead.

Available As

Specialty FKM Product Types

Specialty FKM O-Rings

Precision-molded circular seals available across FITCO's full specialty material range.

View O-Rings →

Specialty FKM Cords

Extruded cord stock in FKM and Silicone — cut, spliced and vulcanized to size.

View Cords →

Specialty FKM O-Ring Kits

Application-specific seal kits in FKM and Silicone, bundled to equipment BOM or drawing.

View O-Ring Kits →
FAQ

Specialty FKM Frequently Asked Questions

Share your fluid, temperature, pressure, movement and any regulatory requirement — FITCO will review and recommend the appropriate grade.

FKM is used as the generic material name. Viton™ is referenced only where the genuine branded product and documentation support the claim.

Send Your Application Details

Share your fluid, temperature, pressure and certification requirement — FITCO will review and propose a suitable Specialty FKM compound.

Send Your Application Details
Material information is provided for preliminary guidance. Final material selection must consider the complete application, including fluid composition and concentration, temperature, pressure, movement, operating cycle, groove design and applicable regulatory requirements. FITCO helps customers identify suitable sealing materials based on application details; this does not constitute a compatibility guarantee.