Fluorosilicone

Fluorosilicone rubber sheet and uncured compound from ElastaPro provides excellent chemical resistance to petroleum oils and hydrocarbon fuels.

• Solid sheet materials come in various thicknesses and widths and arrive ready for die cutting.
• Uncured compound arrives ready for curing and supports calendering, extrusion, and compression molded
• Spec-grade materials meet AMSR25988 (formerly MIL-DTL-25988) requirements and/or AMS specifications.

ElastoPro offers fluorosilicones in low minimum order quantities (MOQs) and with faster turnaround times than you’ll find elsewhere.

Contact us to request a quote or for more information.

Fluorosilicone Rubber Sheet

ElastaPro supplies fluorosilicone rubber sheet (FVMQ) in thicknesses from .010 inches to .500 inches, and in widths up to 65 inches. Choose precut sheets or continuous rolls. Value-added services include custom color-matching and the application of pressure-sensitive adhesive (PSA) backings. Durometers range from 40 to 70 Shore A.

Click the links below for data sheets.

• ESS40FS- 40 Durometer Fluorosilicone
• ESS50FS – 50 Durometer Fluorosilicone
• ESS60FS – 60 Durometer Fluorosilicone
• ESS70FS – 70 Durometer Fluorosilicone

The table below lists typical properties for the fluorosilicone rubber sheet that ElastaPro provides.

Fluorosilicone Uncured Compound

Fluorosilicone uncured compound (FVMQ) arrives ready for curing and can be calendered, extruded, or compression molded. It offers the same high-performance characteristics as the solid fluorosilicone sheet materials we provide.

The following sections provide more fluorosilicones, including their advantages, disadvantages, applications, and specifications.

What is Fluorosilicone Rubber (FVMQ)?

Fluorosilicone rubber (FVMQ) is a specialty elastomer engineered for sealing in chemically aggressive and thermally extreme environments. Unlike standard silicone (VMQ), fluorosilicone rubber incorporates trifluoropropyl side groups into its polymer backbone, which dramatically enhances resistance to fuels, aromatic hydrocarbons, solvents, and mineral oils. This dual chemistry combines the low‑temperature flexibility of silicone with the chemical inertness of fluorocarbon rubber.

• Operating range: typically -65°C to +200°C, with reliable elasticity across cycles.
• Compression set: improved in certain formulations, but gland design must mitigate extrusion risks.
• Limitations: poor abrasion resistance and incompatibility with phosphate esters or amines.

Typically, fluorosilicone rubber is specified when mission-critical seals must endure both temperature extremes and aggressive chemical exposure.

Fluorosilicone Rubber vs. Silicone Rubber

Standard silicone is used for applications that require thermal stability without aggressive chemical contact. In general, fluorosilicone is chosen when chemical exposure to fuels/solvents is unavoidable. See the table below for more information.

Fluorosilicone Advantages and Disadvantages

Fluorosilicone provides many benefits, but it also comes with tradeoffs.

Fluorosilicone Advantages

Fluorosilicone’s advantages include fuel, oil, and solvent resistance along with wide temperature range and thermal stability, low-temperature flexibility and resistance, and suitability for demanding applications.

• Fuel, Oil, and Solvent Resistance: Fluorosilicones exhibit superior resistance to hydrocarbon-based fuels, petroleum oils, mineral oils, and many common solvents. This makes it particularly usel in fuel systems, lubrication systems, and solvent-rich chemical environments. Fluorosilicone also tends to resist aromatic hydrocarbons and many chlorinated or halogenated solvents.
• Wide Temperature Range and Thermal Stability: Fluorosilicones remain flexible and maintain their sealing integrity across a very wide temperature range, typically from around –65 °C (–75 to –100 °F) on the low end up to +200 °C (≈ 400 °F) on the high end for many compounds. Specialized materials can have upper-use limits as high as ~232–260 °C, depending on formulation and conditions. Fluorosilicone also resists weathering, ozone, UV exposure, and the effects of thermal aging.
• Low-Temperature Flexibility and Resistance: Compared with fluoroelastomers like Viton® (FKM), fluorosilicone tends to retain its elasticity and resilience. This includes resistance to compression set and the ability to recover after deformation. Because of its silicone-based backbone, fluorosilicone often performs better than FKM at lower temperatures (cold weather environments). This is an important asset during “cold start” conditions in fuel or oil systems.
• Suitability for Demanding Applications: With its combined chemical and thermal resilience, fluorosilicone is used widely in aerospace fuel and oil systems, automotive fuel emission control systems, chemical-processing seals, and static-seal applications. Its fuel/oil resistance and stability under thermal cycling make it appropriate for molded parts, extrusions, tubing, gaskets, and O-rings in demanding environments.

Fluorosilicone Disadvantages

Fluorosilicone’s disadvantages include its poor mechanical strength, high friction and poor dynamic performance, non-universal chemical compatibility, and higher cost.

• Poor Mechanical Strength, Tear and Abrasion Resistance: Fluorosilicone generally has lower tear strength, poor abrasion resistance, and limited overall mechanical robustness compared with many other elastomers, including FKM and general-purpose rubbers. Consequently, it’s often unsuitable for dynamic sealing applications (e.g., rotating shafts, reciprocating pistons, dynamic packings) where wear, friction, or abrasion are significant.
• High Friction and Poor Dynamic Performance: Fluorosilicone tends to have higher friction, which, coupled with its poor abrasion resistance, makes it a poor choice for dynamic seals. Its gas-permeation resistance also tends to be relatively poor compared with some other elastomers. This can complicate fluorosilicone’s use in vacuum systems or high-pressure gas sealing applications over long periods.
• Chemical Compatibility is Not Universal: Fluorosilicone withstands many hydrocarbons and mineral oils, but it’s not compatible with all chemicals. For example, certain fluids — such as phosphate-ester based hydraulic fluids, hydrazine, strong ketones, or other aggressive chemicals — may degrade FVMQ or cause swelling, hardening, or failure. Concentrated acids, strong alkalis, or aggressive oxidizing chemicals may also exceed  this material’s limits of resistance.
• Higher Cost and Material Traceability: Fluorosilicone tends to cost more than general-purpose silicone or simple elastomers, partly due to its specialty chemistry and partly due to the rigorous testing and certification that’s often required (especially in aerospace or defense contexts). Additionally, because not all fluorosilicone compounds are equal, choosing the right durometer, formulation, and verifying batch testing/traceability can be critical.

Fluorosilicone Strengths vs. Weaknesses

The table below summarizes fluorosilicone’s strengths and weaknesses.

Fluorosilicone Chemical Compatibility

Fluorosilicones provide excellent resistance to petroleum oils and hydrocarbon fluids, but they do not resist all chemicals.

The tables below cover chemical compatibility and use the following ratings system.

• Excellent (A): Fully compatible, very low swelling, maintains physical properties
• Good (B): Minor swelling or property change; generally acceptable
• Fair (C): Significant swelling or degradation; use caution
• Poor (D): Not compatible; severe degradation
• NR: Not recommended / data insufficient

Important: These are typical values, so make sure to confirm a fluorosilicone’s compatibility with the fuel, oil, solvent, or chemical in your application under the expected service conditions.

Fuels

Oils and Lubricants

Solvents

Water and Coolants

Chemicals and Industrial Fluids

Aerospace and Specialty Chemicals

Food and Pharmaceutical Chemicals

Summary Table (Condensed)

Fluorosilicone Applications

Because of its unique combination of fuel resistance, temperature stability, and sealing performance, fluorosilicone is used in demanding industries. Here are some examples.

• Fuel seals and O-rings in aircraft fuel systems: In aerospace, where fuel exposure, vibration, and temperature cycling are common, fluorosilicone is often used for fuel system seals, tank seals, fuel pump seals, and static gaskets. Materials used for these are often certified to AMSR25988 / MIL-DTL-25988.
• Automotive turbocharger seals, fuel hoses, and fuel/emissions control systems: In automotive or turbocharged engines — where exposure to gasoline, diesel, or aromatic fuels plus wide temperature swings occur — fluorosilicone O-rings, gaskets, or hose seals are used to ensure reliability and avoid swelling or degradation.
• Static seals in chemical processing, pumps, compressors, and instrumentation: When enclosures, pump housings, or instrumentation gear are exposed to fuels, solvents, or hydrocarbon-based fluids — especially under varying thermal or environmental conditions — fluorosilicone seals, gaskets, or extruded profiles are used to maintain chemical resistance and sealing integrity.
• Seals for diester-based engine oils or lubricants: Because certain fluorosilicone formulations are compatible with diester oils, they are used in engine systems, lubrication circuits, or mechanical assemblies where synthetic diester oils are employed rather than conventional mineral oils.

In general, fluorosilicone is most often used in aerospace, defense, automotive, petrochemical, and industrial fluid-handling applications wherever a dependable static seal is required under exposure to fuels/oils plus temperature extremes.

Fluorosilicone Specifications

There are several specifications for fluorosilicone rubber.

AMSR25988 (formerly MIL‑DTL‑25988)

AMSR25988 (also referred to as MIL-DTL-25988) is the principal specification for oil- and fuel-resistant fluorosilicone elastomer sheets, strips, molded parts, and extruded shapes for aerospace applications. Materials conforming to AMSR25988 are typically tested for properties including hardness, tensile strength, elongation, compression set, fluid immersion/fuel immersion (e.g., per TT-S-735), low-temperature retraction (e.g., ASTM D1329), aging (e.g., ASTM D573), fluid resistance / swell, and more.

These are the specific spec grade fluorosilicone rubber sheet that ElastaPro makes.

• AMSR25988 TY 2 CL1 GR40

• AMSR25988 TY2 CL1 GR50

• AMSR25988 TY2 CL1 GR60

• AMSR25988 TY2 CL1 GR70

Important: Solid fluorosilicone rubber sheet from ElastaPro meets both AMSR25988 TY2 CL1 GR specifications and AMS3325 requirements.

Aerospace Material Specifications

Fluorosilicones can also meet AMS specifications from SAE International. ElastoPro makes these materials.

• AMS3325

• AMS3326

• AMS3327

Fluorosilicone vs. Flourosilicone and Fluoro Silicone

Made in USA Fluorosilicones

Flurosilicones from ElastaPro are domestically produced in Santa Fe Springs, California. These proven materials are also available with a full Certificate of Analysis (COA) for ever batch. Our COAs include key specifications such as tensile strength, elongation, compression set, hardness, and the results of temperature range testing. ElastaPro also performs a full qualification when there’s a change to a specification or we update a raw material. Plus, we conduct full lot-to-lot verification in accordance with the spec.  This spec uses a table (Table IV) for testing during the lot-to-lot qualification work, and we follow this procedure.

Choose Fluorosilicones from ElastaPro

Selecting the right material is critical for the success of any project. ElastaPro offers reliable and high-performance solutions. Contact ElastaPro today to discuss your needs and discover the right solution for your application.