Viton™ GLT and GFLT are low-temperature specialist grades, purpose-built to preserve cold flexibility down to -40°F/-40°C — well beyond standard Viton A/B/F's practical cold limit — while maintaining FKM's fluid resistance. GFLT adds the higher fluorine content of an F-type grade on top of GLT's cold performance, for applications needing both. FITCO supplies these where a project spec explicitly calls for low-temperature FKM rather than defaulting to FFKM.
| Temperature range | -40°C to +200°C |
|---|---|
| Hardness range | 60–90 Shore A |
| Relative cost | $$$$ |
| Resists | Same broad fluid resistance as standard FKM, plus significantly better low-temperature flexibility |
| Avoid with | Ketones, amines, and the general limits of standard FKM chemistry |
| Standards | AS568 / ISO 3601 / BS 4518 |
General-purpose seal for mineral oils, fuels and hydraulic fluids.
-20°C to +200°CHigh-temperature, chemical-resistant sealing for oil & gas and process industries.
-15°C to +327°CNear-universal chemical resistance for the most demanding process seals.
FEP encapsulated O-rings use standard Silicone or standard Viton FKM as the elastomer core — not specialty sub-grades. If you need FEP encapsulation, the core is standard FKM, not this specific grade.
Standard FKM details → Specialty ProductThin PTFE coating on the FKM O-ring surface — reduced assembly friction, anti-stick, dry lubrication for production line assembly without grease.
PTFE Coated O-Rings → Custom SizesNon-standard ID or cross-section? FITCO manufactures custom O-rings in all Viton grades to any dimension — send your drawing or ID × CS in mm.
Custom O-Ring sizes →Send us your fluid, temperature and pressure — our engineers will confirm the compound.
