Fluoroelastomers (FKM) are most commonly known by the trade name Viton®, but are available from several other manufacturers including 3M, Solvay, and Daikin.

General purpose Fluoroelastomers are copolymers of vinylidene fluoride and hexafluoropropylene and usually have a fluorine content of about 66%. These materials have very good high temperature properties and are resistant to a wide range of chemicals and petroleum based oils. Grades are available for food processing, medical and other specialty applications. Black and Brown are the standard colors, but several others are available.

Specialty Fluoroelastomers are typically terpolymers. Many can be used in a range of applications including concentrated acids, water and steam, automotive fuels, and a wider variety of chemicals. Peroxide cured Fluoroelastomers add additional chemical resistance. The fluorine content in specialty FKM polymers varies between 63 and 70%.

The service temperature of FKM materials can be as high as 500ºF (260º C) on the upper end. Fluoroelastomers generally do not have especially good low temperature properties, but specialty compounds will perform to -50ºF (-45ºC). PAI offers FKM compounds in a hardness range from 55 to 90 durometer.