NITI Ventures

FKM O-Rings

FKM is a premium fluoroelastomer family used where O-rings must handle higher temperatures, fuels, oils, and broader chemical exposure than standard NBR can typically manage. It is often the upgrade choice when the service is hotter or more chemical-intensive.

Typical temperature rangeAbout -20°C to +200°C typical, with short-term peaks higher in some formulations.

Other namesFKM, Fluoroelastomer, Fluorocarbon rubber

Hardness optionsCommon hardness options include 60, 70, 75, 80, and 90 Shore A, depending on compound.

Compliance optionsDepending on compound, FKM may be available with FDA-compliant options, USP Class VI options, REACH / RoHS declarations, and other application-specific approvals.

Best used for

High-temperature oil sealing
Fuel systems
Aggressive industrial fluids
Chemical service
Low gas permeability applications

Key advantages

Excellent high-temperature resistance
Broad chemical resistance
Very good resistance to oils and fuels
Strong ozone, weathering, and aging resistance

Performs well in

Mineral oils
Lubricating oils
Diesel and many fuels
Many hydrocarbons
A broad range of industrial chemicals
Aggressive media in many industrial applications

Use with caution or avoid

Very low-temperature service beyond the compound limit
Hot water or steam unless the grade is specifically suited
Applications needing compound-by-compound chemical verification
Cases where extreme low-temperature flexibility is critical

Typical applications

Fuel systems
Oil sealing systems
Automotive engines and transmissions
Pumps and compressors
Chemical processing equipment
High-temperature static seals

Common industries

Automotive
Chemical processing
Industrial manufacturing
Oil and gas
Fluid handling
High-performance industrial service

When to choose FKM

Choose FKM when you need better heat resistance than NBR, strong resistance to oils and fuels, better long-term sealing in demanding industrial conditions, and broader chemical resistance.

When not to choose FKM: Avoid or review carefully when your application involves very low temperatures, hot water and steam without a suitable grade, or where another material already meets the need more economically.

Selection guide

This is a practical selection guide. Final material choice should always be checked against actual fluid, temperature, pressure, movement, environment, and any approval requirement for the exact compound.

Other materials

Need help selecting the right material?

Tell us your fluid, temperature, pressure, size, and whether the seal is static or dynamic. We can help review the most suitable starting options before final size and compound selection.