FKM (Viton®-type) (fluoroelastomer, typically 75 Shore A) is specified where temperature or chemical exposure exceeds nitrile. Specified on o-ring seal it determines the corrosion behaviour (excellent resistance to heat, fuels, and most chemicals; poor with ketones and hot water/steam) and the service temperature range (approx. -20 °C to +200 °C); the dimensions are ours rather than a standard's, and are listed in full below.
Why Choose FKM (Viton®-type) for O-Ring Seal — ISO / DIN (Series 159)
Specified where temperature or chemical exposure exceeds nitrile. For o-ring seal — iso / din (series 159), this matters when excellent resistance to heat, fuels, and most chemicals; poor with ketones and hot water/steam is the primary requirement.
Mechanical & Physical Properties
| Grade designation | fluoroelastomer, typically 75 Shore A |
|---|---|
| Magnetic response | Non-magnetic |
| Service temperature | approx. -20 °C to +200 °C |
| Corrosion characteristic | Excellent resistance to heat, fuels, and most chemicals; poor with ketones and hot water/steam |
Corrosion Behavior in Service
Carbon and alloy steel o-ring seal — iso / din (series 159) require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Galvanic & Galling Considerations
Galvanic and galling behavior do not apply to o-ring seal — iso / din (series 159) in FKM (Viton®-type) — the relevant compatibility questions are chemical: confirm the elastomer against the fluid, the temperature and any cleaning agents in service, and check the gland or groove dimensions give the intended compression on the section.
Sizes of O-Ring Seal — ISO / DIN (Series 159) Available in FKM (Viton®-type)
| Inner diameter d1 (mm) | Outer diameter d2 (mm) | Wire dia (mm) | Working temp range | Reference standard |
|---|---|---|---|---|
| 5 | 9 | 2 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 8 | 12 | 2 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 10 | 16 | 3 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 15 | 21 | 3 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 20 | 26 | 3 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 25 | 33 | 4 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 30 | 38 | 4 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 40 | 50 | 5 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 50 | 60 | 5 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 60 | 72 | 6 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 80 | 92 | 6 | -30 to +110 C | ISO 3601 / GB/T 3452 |
| 100 | 114 | 7 | -30 to +110 C | ISO 3601 / GB/T 3452 |
Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in FKM (Viton®-type). The catalogue's default material column has been omitted here so it cannot be read as contradicting that.
Custom manufacturing · Made to drawing
Need this seal in a grade that is not listed?
Fkm is one of the grades the catalog describes. Inside diameter, cross-section and compound are the three that matter, and the compound is chosen against the fluid and the temperature rather than the dimensions.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
