FKM (Fluoroelastomer / Viton) vs NBR (Nitrile Rubber): 0% composition overlap. Significantly different materials serving different application areas.
FKM (Fluoroelastomer / Viton) vs NBR (Nitrile Rubber)
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.
NBR (Nitrile Rubber)
Nitrile butadiene rubber (Buna-N) — THE oil and fuel resistant elastomer. ACN content (18-50%) determines the oil resistance vs low-temp flexibility tradeoff. Higher ACN = better oil resistance but stiffer at low temp. The most widely used seal material worldwide. Used for O-rings, fuel hoses, gaskets, hydraulic seals, oil seals, and nitrile gloves. Not suitable for ozone, UV, or polar solvents (ketones, esters). HNBR variant for higher heat resistance.
| FKM (Fluoroelastomer / Viton) | NBR (Nitrile Rubber) | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | ISO 37 | ISO 37 |
Mechanical properties
| Property | FKM (Fluoroelastomer / Viton) | NBR (Nitrile Rubber) | Unit |
|---|---|---|---|
| tensile_strength | 8–17 | 7–24 | MPa |
| elongation | 150–350 | 200–600 | % |
| hardness_shore_a | 60–90 | 40–90 | Shore A |
Compatibility Assessment
FKM (Fluoroelastomer / Viton) and NBR (Nitrile Rubber) 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 NBR (Nitrile Rubber)?
FKM (Fluoroelastomer / Viton) and NBR (Nitrile Rubber) have a 0% composition overlap. They are generally not directly interchangeable.
Can I replace FKM (Fluoroelastomer / Viton) with NBR (Nitrile Rubber)?
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 NBR (Nitrile Rubber)?
The main differences are in the following elements: overall alloying content. FKM (Fluoroelastomer / Viton) is a Polymers grade, while NBR (Nitrile Rubber) 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.