Kalrez 6375 vs Tecnoflon PFR PFR94: FFKM Compound Comparison
Verified by Rachel Mayfield, Supply Chain Analyst - April 2026
Kalrez 6375 and Tecnoflon PFR PFR94 are both perfluoroelastomer (FFKM) compounds used in chemical, refinery, and process applications. Kalrez 6375 vs Tecnoflon PFR PFR94 They share similar chemistry but differ on temperature ceiling, hardness, and intended service. This page compares the two side-by-side and explains when to specify each.
Side-by-side comparison
| Property | Kalrez 6375 | Tecnoflon PFR PFR94 |
|---|---|---|
| Manufacturer | DuPont (Chemours) | Solvay Specialty Polymers |
| Compound | 6375 | PFR94 |
| Maximum continuous temp | 275°C | 230°C |
| Minimum temp | -7°C | -10°C |
| Hardness | 75 Shore A | 75 Shore A |
| Colour | Black | Black |
| Typical applications | Chemical process, pharmaceutical, semiconductor wet etch, hot/cold cycling | Chemical process, pharma |
When to specify Kalrez 6375
Kalrez 6375 suits chemical process and similar service. Continuous temperature window is -7°C to 275°C, hardness 75 Shore A. Manufactured by DuPont (Chemours).
Limitation: Lower temp ceiling than 4079; not for high-purity semiconductor plasma.
When to specify Tecnoflon PFR PFR94
Tecnoflon PFR PFR94 suits chemical process and similar service. Continuous temperature window is -10°C to 230°C, hardness 75 Shore A. Manufactured by Solvay Specialty Polymers.
Key differences
- Temperature ceiling: Kalrez 6375 runs 45°C hotter (275°C vs 230°C). Specify the higher-rated compound when continuous service is above 230°C.
- Hardness: Both are 75 Shore A, so groove design and squeeze percentage are interchangeable.
- Manufacturer: Kalrez 6375 is from DuPont (Chemours); Tecnoflon PFR PFR94 is from Solvay Specialty Polymers. Lead time and UK availability vary by brand.
- Cost: FFKM pricing varies by manufacturer, batch size, and stock position. Both compounds are at the premium end of elastomer pricing (£30 to £500+ per O-ring depending on size).
Get a UK quote on either compound
Related pages
Frequently Asked Questions
Can I substitute Kalrez 6375 for Tecnoflon PFR PFR94?
Yes, Kalrez 6375 and Tecnoflon PFR PFR94 are both FFKM compounds with overlapping chemical compatibility. Verify your specific fluid against both manufacturers' compatibility tables before substitution. Temperature window, hardness, and certifications may differ.
Which is hotter: Kalrez 6375 or Tecnoflon PFR PFR94?
Kalrez 6375 has a higher continuous temperature ceiling (275°C vs 230°C, a 45°C difference).
Which costs less: Kalrez 6375 or Tecnoflon PFR PFR94?
FFKM compound pricing depends on manufacturer, batch size, certifications, and current stock position rather than headline brand. Both compounds are at the premium end of elastomer pricing. Get current UK quotes on both before specifying.
Where can I buy Kalrez 6375 or Tecnoflon PFR PFR94 in the UK?
Both compounds are supplied in the UK by independent FFKM seal specialists carrying multiple manufacturer lines. Lead time is typically 2-5 working days for stock BS 1806 / AS568 sizes, 4-8 weeks for custom-moulded sizes.