FKM (Fluoroelastomer / Viton) vs PA66 (Nylon 66): 0% composition overlap. Significantly different materials serving different application areas.
FKM (Fluoroelastomer / Viton) vs PA66 (Nylon 66)
Side-by-side chemical composition and mechanical property comparison.
Overview
FKM (Fluoroelastomer / Viton)
Fluoroelastomer — THE high-temperature and chemical-resistant rubber. Outstanding resistance to oils, fuels, acids, and solvents at temperatures up to 200°C (short-term 230°C). Fluorine content (64-70%) determines chemical resistance. Trade names: Viton (Chemours), Tecnoflon (Solvay), Dai-El (Daikin). 5-10x more expensive than NBR. Used for aerospace fuel seals, chemical process seals, automotive fuel injector O-rings, semiconductor processing, and any seal exposed to aggressive chemicals at high temperature.
PA66 (Nylon 66)
Polyamide 66 — stiffer and more heat-resistant than PA6. Higher crystallinity gives better creep resistance and ~40°C higher melting point (260°C vs 220°C). Slightly more brittle. More moisture-sensitive at saturation than PA6. Trade names include Ultramid A (BASF), Zytel 101 (DuPont), Tecamid 66 (Ensinger). Dominant in US/UK markets. Used for automotive engine components, electrical connectors, gears, cable ties, and industrial bushings.
| FKM (Fluoroelastomer / Viton) | PA66 (Nylon 66) | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | ISO 37 | ISO 10350 |
Chemical composition (wt%) — Pro
| Element | FKM (Fluoroelastomer / Viton) | PA66 (Nylon 66) | Overlap |
|---|---|---|---|
| Vinylidene Fluoride (VDF) | 30–60% | — | — |
| Hexafluoropropylene (HFP) | 25–45% | — | — |
| Tetrafluoroethylene (TFE) | 0–30% | — | — |
| Hexamethylenediamine unit | — | 45–55% | — |
| Adipic Acid unit |
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Sign up free — 3 comparisons/day freeMechanical properties — Pro
| Property | FKM (Fluoroelastomer / Viton) | PA66 (Nylon 66) | Unit |
|---|---|---|---|
| Tensile Strength | 8–17 | 80–90 | MPa |
| Elongation | 150–350 | 15–40 | % |
| hardness_shore_a | 60–90 | — | Shore A |
| Density | |||
| continuous_service_temp | |||
| Yield Strength | |||
| Elastic Modulus | |||
| Melting Point | |||
| Glass Transition Temp (Tg) | |||
| Water Absorption (24h) | |||
| Tensile Strength | |||
| Tensile Modulus | |||
| Elongation at Break | |||
| Charpy Impact (notched) | |||
| Density | |||
| Melting Point | |||
| Glass Transition Temp | |||
| Water Absorption (24h) | |||
| Water Absorption (saturation) |
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Sign up free — 3 comparisons/day freeCompatibility Assessment
FKM (Fluoroelastomer / Viton) and PA66 (Nylon 66) have significantly different compositions (0% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is FKM (Fluoroelastomer / Viton) the same as PA66 (Nylon 66)?
FKM (Fluoroelastomer / Viton) and PA66 (Nylon 66) have a 0% composition overlap. They are generally not directly interchangeable.
Can I replace FKM (Fluoroelastomer / Viton) with PA66 (Nylon 66)?
Generally not recommended. The compositions differ significantly (0% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between FKM (Fluoroelastomer / Viton) and PA66 (Nylon 66)?
The main differences are in the following elements: overall alloying content. FKM (Fluoroelastomer / Viton) is a Polymers grade, while PA66 (Nylon 66) is a Polymers grade.
Related Comparisons
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Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.