FKM (Fluoroelastomer / Viton) vs PBT (unfilled): 0% composition overlap. Significantly different materials serving different application areas.
FKM (Fluoroelastomer / Viton) vs PBT (unfilled)
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.
PBT (unfilled)
Polybutylene Terephthalate — semi-crystalline polyester with fast crystallization (short cycle times), very low moisture absorption (0.15%), excellent dimensional stability, and good electrical properties. Key advantage over PA: properties nearly independent of humidity. Trade names include Ultradur (BASF), Celanex/Crastin (Celanese/DuPont), Valox (SABIC), Arnite T (DSM). Used for electrical connectors, relay housings, automotive sensors, and any precision part in humid environments.
| FKM (Fluoroelastomer / Viton) | PBT (unfilled) | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | ISO 37 | ISO 10350 |
Mechanical properties
| Property | FKM (Fluoroelastomer / Viton) | PBT (unfilled) | Unit |
|---|---|---|---|
| tensile_strength | 8–17 | 50–65 | MPa |
| elongation | 150–350 | 50–100 | % |
| hardness_shore_a | 60–90 | — | Shore A |
Compatibility Assessment
FKM (Fluoroelastomer / Viton) and PBT (unfilled) 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 PBT (unfilled)?
FKM (Fluoroelastomer / Viton) and PBT (unfilled) have a 0% composition overlap. They are generally not directly interchangeable.
Can I replace FKM (Fluoroelastomer / Viton) with PBT (unfilled)?
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 PBT (unfilled)?
The main differences are in the following elements: overall alloying content. FKM (Fluoroelastomer / Viton) is a Polymers grade, while PBT (unfilled) 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.