FKM vs. Viton

Attribute	FKM	Viton
Chemical Resistance	Excellent	Excellent
Temperature Range	-20°C to 200°C	-20°C to 200°C
Hardness Range	50 to 90 Shore A	50 to 90 Shore A
Compression Set	Good	Good
Tensile Strength	Good	Good

Introduction

FKM and Viton are two popular types of elastomers that are widely used in various industries for their excellent chemical resistance and high temperature capabilities. While they are often used interchangeably, there are some key differences between the two materials that are important to consider when selecting the right material for a specific application.

Chemical Composition

FKM, which stands for Fluoroelastomer, is a synthetic rubber that is made up of fluorine, carbon, and hydrogen atoms. It is known for its exceptional resistance to a wide range of chemicals, oils, and solvents. Viton, on the other hand, is a brand of FKM that is specifically made by the company DuPont. While Viton is technically a type of FKM, it is often used as a generic term to refer to all fluoroelastomers.

Temperature Resistance

One of the key advantages of both FKM and Viton is their ability to withstand high temperatures. FKM can typically handle temperatures ranging from -20°C to 200°C, while Viton can withstand temperatures up to 250°C. This makes both materials ideal for applications where heat resistance is crucial, such as in automotive engines and industrial machinery.

Compression Set

Compression set refers to the ability of a material to return to its original shape after being compressed. FKM generally has a lower compression set compared to other elastomers, which means it can maintain its sealing properties over a longer period of time. Viton, being a type of FKM, also exhibits low compression set characteristics, making it a reliable choice for sealing applications.

Cost

When it comes to cost, FKM and Viton are typically more expensive than other types of elastomers due to their superior chemical resistance and high temperature capabilities. However, the cost of Viton can be slightly higher than generic FKM due to its brand recognition and reputation for quality. It is important to consider the overall performance requirements of the application when evaluating the cost-effectiveness of these materials.

Compatibility

Both FKM and Viton are compatible with a wide range of fluids, including oils, fuels, and solvents. They are also resistant to harsh chemicals and can withstand exposure to ozone and UV radiation. This makes them suitable for use in demanding environments where other elastomers may degrade or fail. It is important to consult with a material specialist to ensure that FKM or Viton is the right choice for the specific application.

Conclusion

In conclusion, FKM and Viton are two versatile elastomers that offer excellent chemical resistance, high temperature capabilities, and low compression set characteristics. While they share many similarities, there are some key differences between the two materials that may influence the selection process. By understanding the unique attributes of FKM and Viton, engineers and designers can make informed decisions when choosing the right material for their applications.