Fuel resistance
Resists swelling in fuels and oils better than standard silicone.
Fluorosilicone
Fluorosilicone: Properties, Applications and Design Guide
Fluorosilicone explained for comparison with thermoplastic elastomers. NetProto focuses on thermoplastic molding and overmolding.
Fluorosilicone
What Fluorosilicone is and when it is used
Education page. Silicone molding is outside NetProto's thermoplastic scope.
Fluorosilicone is a silicone elastomer modified with fluorine groups, so it keeps the wide temperature range of silicone while adding resistance to fuels, oils, and many solvents. It is used for fuel system seals, O-rings, and gaskets where standard silicone would swell. Like LSR, it is a thermoset processed on silicone equipment, not a thermoplastic. NetProto focuses on thermoplastic molding and overmolding. This page explains fluorosilicone for comparison so you can check whether a thermoplastic elastomer or a fluoropolymer fits your part.
Key traits
Why engineers specify Fluorosilicone
Material characteristics for comparison. No processing parameters on this page.
Temperature range
Keeps silicone flexibility across hot and cold service.
Process
Thermoset silicone processing, not melt and cool.
Alternatives
TPV, fluoropolymers, or TPU may fit when heat allows.
Routing
Fluorosilicone or a thermoplastic alternative
Pick the material family by the requirement that matters most.
| Requirement | Start with | Why |
|---|---|---|
| Fuel and oil sealing across wide temperature | Fluorosilicone | Silicone range plus fuel resistance |
| General high-heat seals without fuel | LSR | Standard silicone |
| Moderate heat seals and gaskets | TPV | Thermoplastic seal option |
| Rigid chemical-resistant parts | PVDF | Melt-processable fluoropolymer |
Selection
Selection checklist
Use these points to decide between silicone and a thermoplastic elastomer.
Fuels, oils, or solvents the seal must resist
Service temperature range, including cold flexibility
Hardness range (Shore A)
Regulatory documentation your program requires (from the supplier)
Seal geometry and compression requirement
Whether a thermoplastic option could meet the same requirement
Compare and explore
Related materials
Thermoplastic alternatives and sibling pages.
Silicone (LSR)
Standard liquid silicone rubber.
Learn more
TPV (Santoprene)
Thermoplastic seal option.
Learn more
PVDF
Chemical-resistant fluoropolymer.
Learn more
TPE family hub
Thermoplastic elastomer routing.
Learn more
Reading a material datasheet
What the TDS values mean for a molded part.
Reading a material datasheetFAQ
Fluorosilicone FAQ
What is the difference between fluorosilicone and standard silicone?
Fluorosilicone adds fluorine groups that reduce swelling in fuels and oils, while standard silicone swells in many hydrocarbons. NetProto explains both for comparison and focuses its molding on thermoplastics.
Does NetProto mold fluorosilicone parts?
No. Fluorosilicone is a thermoset silicone, and NetProto focuses on thermoplastic injection molding and overmolding. For thermoplastic seal options, see the TPV and TPE pages.
When could TPV replace fluorosilicone?
When the seal sees moderate heat and limited fuel exposure, a TPV grade may meet the requirement. At NetProto, we suggest checking compression set and fluid exposure on the TPV page before committing to a silicone supply chain.
Is fluorosilicone a fluoropolymer like PVDF?
No. Fluorosilicone is a flexible silicone elastomer, while PVDF is a rigid melt-processable fluoropolymer. NetProto can discuss PVDF for rigid chemical-resistant parts on the PVDF page.
Who provides compliance documentation for fluorosilicone?
Documentation comes from the material supplier and the molder that processes it. NetProto does not make regulatory claims for fluorosilicone parts.
Why is fluorosilicone more expensive than silicone?
The fluorinated chemistry costs more to produce, so it is usually reserved for fuel and oil contact. NetProto recommends using it only where standard silicone or a thermoplastic elastomer cannot meet the requirement.
Next step
Considering a thermoplastic alternative?
Compare TPE and TPV options, or review how rigid and soft thermoplastics are overmolded.