Fluorosilicone (FVMQ) & Fluoroelastomer (FKM)
Fluorosilicone (FVMQ) combines the wide temperature range and flexibility of silicone with resistance to fuels, oils, and solvents. Trifluoropropyl side chains on the silicone backbone give it hydrocarbon resistance that ordinary VMQ silicone lacks, while keeping silicone’s characteristic low-temperature flexibility and low compression set. Where chemical attack is even more aggressive, we also process fluoroelastomer (FKM/Viton-type) compounds for concentrated acids, aromatics, and high-temperature industrial service.
Material Data
FVMQ Material Specifications
| Typical service temperature | -60°C to +200°C (MIL-DTL-25988 Class 1/2; Class 3 to +225°C) |
|---|---|
| Hardness range | 40 to 80 Shore A |
| Compression set | Low — retains seal force over long static duty |
| Fuel & oil resistance | Excellent vs jet fuels (JP-5/JP-8), gasoline, diesel, synthetic lubricants |
| Low-temperature flexibility | Excellent — stays flexible where FKM stiffens |
| Flame behavior | Self-extinguishing; chars rather than sustaining flame |
| Key spec | MIL-DTL-25988 (sheet, strip, molded parts, extruded shapes) |
Selection Guide
FVMQ vs FKM vs VMQ — How to Choose
| Continuous temp | -60 to +200°C |
|---|---|
| Fuel / oil resistance | Excellent |
| Concentrated acids / ketones | Fair |
| Low-temp flexibility | Excellent |
| Compression set | Low |
| Mechanical strength | Moderate |
| Typical cost | High |
| Where chosen | Aerospace fuel systems, cold-climate fuel seals |
Standards
MIL-DTL-25988 Capability
For defense and aerospace programs we process compounds qualified to MIL-DTL-25988: Type I for molded shapes and O-rings requiring ultra-low compression set, Type II for calendered sheet and cut gaskets where tear resistance and dimensional tolerance are critical. Classes define temperature ratings: Class 1/2 to +200°C, Class 3 to +225°C.
Products
Products We Manufacture
- O-rings & cord stock (fuel and hydraulic systems)
- Cut & molded gaskets (MIL-DTL-25988 Type II sheet)
- Diaphragms & valve seals (fuel metering, emission control)
- Connector seals & boots (aerospace harness, sensor housings)
- Extruded profiles & tubing (fuel vent, oil sensing lines)
- Custom molded parts from customer drawings (compression / injection)
Applications
Applications
- Aerospace — fuel system seals, tank access gaskets, engine accessory seals (JP-5/JP-8 exposure)
- Automotive — fuel rail seals, oil sensor housings, EV battery coolant seals
- Defense — vehicle fuel systems, hydraulic seals per MIL-DTL-25988
- Industrial — chemical pump seals, solvent-resistant diaphragms, metering valve seats
- Oil & gas — downhole sensing seals, fuel-handling equipment
FAQ
Fluorosilicone & Fluoroelastomer FAQ
When should I choose FVMQ instead of FKM?
Choose FVMQ when you need fuel/oil resistance AND low-temperature flexibility (below -20°C), or where the seal must stay compliant under thermal cycling. Choose FKM for concentrated acids, aromatics, ketones, or the highest mechanical strength in hot aggressive media.
What standards cover fluorosilicone parts?
MIL-DTL-25988 is the principal specification for FVMQ sheet, strip, molded parts and extruded shapes. Aerospace and defense customers typically reference it directly; commercial programs adopt equivalent internal specs.
Can you mold fluorosilicone with tight tolerances?
Yes. We compression- and injection-mold FVMQ with controlled cure, then verify dimensions and compression set per drawing. O-ring and gasket tolerances follow ISO 3601 / MIL-DTL-25988 classes as required.
What fuels and fluids is FVMQ resistant to?
Jet fuels (JP-5, JP-8, Jet A), gasoline (including oxygenated blends), diesel, kerosene, synthetic ester lubricants, and many hydraulic fluids. It is not recommended for concentrated strong acids, ketones, or steam service.
Do you supply FKM (Viton-type) as well?
Yes — we process both FVMQ and FKM. Send us the media, temperature, and pressure conditions and we will recommend the compound family, hardness, and cure system.
What information do you need for a quote?
Drawing or sample, exposure media, temperature range, quantity, and any certification requirement (MIL spec, material certs, PPAP). We respond within 24 hours with a DFM note and quotation.
Send us your drawing or sample
Media, temperature, pressure, quantity — we recommend the compound and quote within 24 hours.
Request a QuoteReal Parts
Sealing Parts — FKM · FVMQ · EPDM · HNBR · FFKM.
O-rings, compressor seals, IGBT sealing rings, water-cooled sealing rings and high-precision metal-overmolded seals.
