FKM (Fluoroelastomer / Viton) vs FR-4 (Glass Epoxy Laminate): 0% composition overlap. Significantly different materials serving different application areas.
FKM (Fluoroelastomer / Viton) vs FR-4 (Glass Epoxy Laminate)
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.
FR-4 (Glass Epoxy Laminate)
Flame retardant woven fiberglass cloth with epoxy resin binder — the worldwide standard substrate material for printed circuit boards (PCBs). Designated NEMA grade FR-4 and IPC-4101. Good mechanical strength, dimensional stability and electrical insulation up to 130°C (Tg). Dielectric constant 4.2–4.7 at 1 MHz. Self-extinguishing (UL94 V-0). Used for single/multilayer PCBs, electrical insulation boards, structural composites in electronics, test fixtures and jigs. Available in thicknesses 0.1–50 mm.
| FKM (Fluoroelastomer / Viton) | FR-4 (Glass Epoxy Laminate) | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | ISO 37 | IPC-4101 |
Chemical composition (wt%) — Pro
| Element | FKM (Fluoroelastomer / Viton) | FR-4 (Glass Epoxy Laminate) | Overlap |
|---|---|---|---|
| Vinylidene Fluoride (VDF) | 30–60% | — | — |
| Hexafluoropropylene (HFP) | 25–45% | — | — |
| Tetrafluoroethylene (TFE) | 0–30% | — | — |
| Epoxy Resin Matrix | — | 35–45% | — |
| Glass Fiber (E-Glass) Cloth |
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Sign up free — 3 comparisons/day freeMechanical properties — Pro
| Property | FKM (Fluoroelastomer / Viton) | FR-4 (Glass Epoxy Laminate) | Unit |
|---|---|---|---|
| Tensile Strength | 8–17 | — | MPa |
| Elongation | 150–350 | — | % |
| hardness_shore_a | 60–90 | — | Shore A |
| Density | |||
| continuous_service_temp | |||
| Flexural Strength | |||
| Tensile Strength | |||
| Compressive Strength | |||
| Density | |||
| Glass Transition Temp (Tg) | |||
| Dielectric Constant (1MHz) | |||
| Dielectric Strength | |||
| UL94 Flammability | |||
| Water Absorption (24h) |
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Sign up free — 3 comparisons/day freeCompatibility Assessment
FKM (Fluoroelastomer / Viton) and FR-4 (Glass Epoxy Laminate) 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 FR-4 (Glass Epoxy Laminate)?
FKM (Fluoroelastomer / Viton) and FR-4 (Glass Epoxy Laminate) have a 0% composition overlap. They are generally not directly interchangeable.
Can I replace FKM (Fluoroelastomer / Viton) with FR-4 (Glass Epoxy Laminate)?
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 FR-4 (Glass Epoxy Laminate)?
The main differences are in the following elements: overall alloying content. FKM (Fluoroelastomer / Viton) is a Polymers grade, while FR-4 (Glass Epoxy Laminate) is a Polymers grade.
View full data for each material:
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.