Silicone gaskets offer exceptional performance in harsh environments, but not all silicones are the same. Engineers should evaluate durometer, compression set, thermal cycling, chemical resistance, and UV/ozone stability—selecting solid, sponge, foam, or fluorosilicone materials based on application stress and exposure.

What makes silicone gaskets ideal for harsh environments?

Silicone rubber retains flexibility and sealing integrity across a wide temperature range (typically –60 °C to +230 °C) and resists ozone, UV, and weathering better than most elastomers. For applications such as aerospace controls, outdoor telecommunications, or semiconductor tools, silicone gaskets provide long-term sealing stability where EPDM or neoprene would degrade.

Stockwell Elastomerics supplies engineered silicone gasketing materials from industry leaders including Rogers Corporation, Saint-Gobain, and Specialty Silicone Products (SSP). These include:

How do key material properties influence gasket performance?

Selecting a gasket for harsh conditions requires more than specifying “silicone.” The following parameters guide optimal performance:

1.  Firmness

Firmness is measured differently based on the type of material used. For silicone sponges and foams, Compression Force Deflection (CFD) is used. CFD is a measurement of pressure required to deflect a material by 25%.

The CFD of material is typically specified based on the available force to drive compression.

For solid silicones, durometer, measured on the Shore A scale, defines the gasket’s firmness and ability to conform.

• Soft silicones (20–40 A) seal uneven surfaces in static
• Medium silicones (40–60 A) balance compressibility and dimensional
• Hard silicones (60–80 A) withstand mechanical cycling or repeated access

2.  Compression Set

Compression set quantifies a gasket’s ability to rebound after compression.

• Low compression set (<10%) = better recovery and seal
• High compression set = permanent deformation and leak

Silicone’s inherent resilience outperforms many organic elastomers such as neoprene or nitrile.

3.  Thermal Cycling Resistance

Repeated heating and cooling can induce expansion–contraction stresses. Silicone’s low

glass-transition temperature and thermal stability (up to 230 °C continuous, 260 °C intermittent) allow reliable sealing through rapid cycles without cracking or embrittlement.

4.  Chemical Compatibility

Standard silicone resists polar solvents, weak acids, and salts, but not hydrocarbons or concentrated acids.

• Use fluorosilicone where exposure to fuels, oils, or cleaning solvents is expected (e.g., MIL-R-25988 environments).

5.  UV and Ozone Resistance

Silicone’s inorganic Si–O backbone provides exceptional resistance to ozone cracking and UV degradation. This makes it ideal for outdoor applications such as telecom cabinets, LED fixtures, and aerospace radomes.

What engineered silicones are recommended for proven reliability?

Stockwell Elastomerics commonly specifies:

• Rogers HT-800® Series – medium-firm silicone foams for NEMA/UL
• Saint-Gobain R-104XX Series – closed-cell silicone sponges for weatherproof
• SSP 4773 and SSP 4749 Series – silicone and fluorosilicone grades for medical requirements and fuel

All can be die-cut, waterjet-cut, or molded with pressure-sensitive adhesive backings to simplify assembly.

How does Stockwell support engineers specifying materials for extreme conditions?

Stockwell Elastomerics’ applications engineers collaborate directly with design teams to match material performance with environmental exposure. Our in-house R&D engineer supports ongoing formulation testing, adhesive validation, and prototype fabrication—helping customers accelerate qualification for demanding aerospace, defense, and semiconductor sealing projects.

Request a Rapid Silicone Gasket Sample

Partner with Stockwell Elastomerics’ applications engineers to specify, prototype, and validate silicone gasket materials for your harsh environment sealing challenges. Request a rapid silicone gasket sample today.