Materials → Fluorocarbon (FKM)
Material profile · 04/06
FLUOROCARBON (FKM)
High-temperature, chemically resilient elastomer for the harshest operating media.
- -20°C to 200°C
- Temp. range
- 75-90 Shore A
- Hardness
- Medium
- Friction
- Excellent
- Chemical resistance
Overview
Where Fluorocarbon (FKM) earns its place.
Fluorocarbon elastomer (commonly known by the trade name Viton) is specified where NBR runs out of temperature or chemical resistance. It tolerates sustained high heat, resists a wide range of fuels, oils, and process chemicals, and holds its properties in environments that would harden or swell nitrile within months. FKM costs more than NBR, so it is typically reserved for O-rings and rotary seals in high-temperature or chemically demanding installations rather than specified as a blanket replacement.
Trade-offs
Advantages and limitations.
Advantages
- Sustained performance at high continuous operating temperature.
- Resists fuels, mineral and synthetic oils, and many process chemicals.
- Low permeability — useful where fluid or gas loss matters.
- Better ozone and weathering resistance than NBR for outdoor duty.
Limitations
- Significantly higher cost than NBR for equivalent geometry.
- Poor low-temperature flexibility compared with NBR and PU.
- Limited resistance to certain amines, ketones, and low-molecular-weight esters.
Operating envelope
Typical technical reference.
Figures are typical for the compound family and vary by specific grade and cure. Confirm exact limits against your fluid, pressure, and duty cycle before finalising a specification.
| Operating temperature | -20°C to 200°C (grade dependent) |
| Typical hardness | 75-90 Shore A |
| Friction coefficient | Medium |
| Fluid compatibility | Fuels, oils, many aggressive process chemicals |
| Duty type | Static and dynamic — O-rings, rotary seals |
Compare
See the other five materials.
Engineering support
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