FKM (Fluoroelastomer / Viton®) O-rings

-20 °C to 200 °C

FKM (also known as Viton®) is a premium fluoroelastomer with excellent resistance to chemicals, high temperatures, fuels, and aggressive media. A standard in the chemical industry.

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1,494 products

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Low stock
O-ring 145×4 FKM 80 Shore A
Dimensions
145 × 4 mm · OD 153 mm
Material
FKM · 80 ShA
Product code OR-FKM80-145x4
€5.23excl. VAT
Low stock
O-ring 155×5.5 FKM 80 Shore A
Dimensions
155 × 5.5 mm · OD 166 mm
Material
FKM · 80 ShA
Product code OR-FKM80-155x5-5
€5.87excl. VAT
Low stock
O-ring 190×3 FKM 80 Shore A
Dimensions
190 × 3 mm · OD 196 mm
Material
FKM · 80 ShA
Product code OR-FKM80-190x3
€4.43excl. VAT
Low stock
O-ring 196.44×3.53 FKM 80 Shore A
Dimensions
196.44 × 3.53 mm · OD 203.5 mm
Material
FKM · 80 ShA
Product code OR-FKM80-196-44x3-53
€4.03excl. VAT
Low stock
O-ring 200×2 FKM 80 Shore A
Dimensions
200 × 2 mm · OD 204 mm
Material
FKM · 80 ShA
Product code OR-FKM80-200x2
€4.14excl. VAT
Low stock
O-ring 205×2 FKM 80 Shore A
Dimensions
205 × 2 mm · OD 209 mm
Material
FKM · 80 ShA
Product code OR-FKM80-205x2
€4.02excl. VAT
Low stock
O-ring 205×5 FKM 80 Shore A
Dimensions
205 × 5 mm · OD 215 mm
Material
FKM · 80 ShA
Product code OR-FKM80-205x5
€10.00excl. VAT
Low stock
O-ring 235×5 FKM 80 Shore A
Dimensions
235 × 5 mm · OD 245 mm
Material
FKM · 80 ShA
Product code OR-FKM80-235x5
€19.00excl. VAT
Low stock
O-ring 250×3 FKM 80 Shore A
Dimensions
250 × 3 mm · OD 256 mm
Material
FKM · 80 ShA
Product code OR-FKM80-250x3
€5.36excl. VAT
Low stock
O-ring 255×7 FKM 80 Shore A
Dimensions
255 × 7 mm · OD 269 mm
Material
FKM · 80 ShA
Product code OR-FKM80-255x7
€10.50excl. VAT
Low stock
O-ring 285×3 FKM 80 Shore A
Dimensions
285 × 3 mm · OD 291 mm
Material
FKM · 80 ShA
Product code OR-FKM80-285x3
€5.16excl. VAT
Low stock
O-ring 329.57×5.33 FKM 80 Shore A
Dimensions
329.57 × 5.33 mm · OD 340.23 mm
Material
FKM · 80 ShA
Product code OR-FKM80-329-57x5-33
€10.56excl. VAT
Low stock
O-ring 390×3 FKM 80 Shore A
Dimensions
390 × 3 mm · OD 396 mm
Material
FKM · 80 ShA
Product code OR-FKM80-390x3
€9.04excl. VAT
Low stock
O-ring 4.48×1.78 FKM 80 Shore A
Dimensions
4.48 × 1.78 mm · OD 8.04 mm
Material
FKM · 80 ShA
Product code OR-FKM80-4-48x1-78
€0.19excl. VAT
Low stock
O-ring 440×4 FKM 80 Shore A
Dimensions
440 × 4 mm · OD 448 mm
Material
FKM · 80 ShA
Product code OR-FKM80-440x4
€9.06excl. VAT
Available to order
O-ring 113.89×3.53 FKM 70 Shore A
Dimensions
113.89 × 3.53 mm · OD 120.95 mm
Material
FKM · 70 ShA
Product code OR-FKM70-113-89x3-53
€0.78excl. VAT
Available to order
O-ring 50×1.2 FKM 70 Shore A
Dimensions
50 × 1.2 mm · OD 52.4 mm
Material
FKM · 70 ShA
Product code OR-FKM70-50x1-2
€2.86excl. VAT
Available to order
O-ring 10.1×1.6 FKM 80 Shore A
Dimensions
10.1 × 1.6 mm · OD 13.3 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-1x1-6
€0.33excl. VAT
Available to order
O-ring 10.3×2.4 FKM 80 Shore A
Dimensions
10.3 × 2.4 mm · OD 15.1 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-3x2-4
€0.50excl. VAT
Available to order
O-ring 10.52×1.83 FKM 80 Shore A
Dimensions
10.52 × 1.83 mm · OD 14.18 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-52x1-83
€0.33excl. VAT
Available to order
O-ring 10.5×1.5 FKM 80 Shore A
Dimensions
10.5 × 1.5 mm · OD 13.5 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-5x1-5
€0.33excl. VAT
Available to order
O-ring 10.5×2.5 FKM 80 Shore A
Dimensions
10.5 × 2.5 mm · OD 15.5 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-5x2-5
€0.50excl. VAT
Available to order
O-ring 10.5×2.7 FKM 80 Shore A
Dimensions
10.5 × 2.7 mm · OD 15.9 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-5x2-7
€0.50excl. VAT
Available to order
O-ring 10.5×2 FKM 80 Shore A
Dimensions
10.5 × 2 mm · OD 14.5 mm
Material
FKM · 80 ShA
Product code OR-FKM80-10-5x2
€0.50excl. VAT

Temperature and chemical compatibility

Temperature range: -20 °C to +200 °C (short-term up to +230 °C).

Featured products

Typical applications: chemical industry, oil and gas, engine seals, fuel systems, aviation, semiconductors.

FKM (Fluoroelastomer / Viton®)

Each elastomer has different mechanical and chemical properties.

FKM (Fluoroelastomer / Viton®) — properties and applications

FKM (Viton®, fluoroelastomer) is a premium sealing material for high temperatures and aggressive media. FKM O-rings handle temperatures from −20 to +200 °C (briefly up to +230 °C) and are typically supplied at a hardness of 75 ShA, which makes them a reliable choice wherever ordinary rubbers already fail. The material's character is clear-cut: performance under thermal and chemical load, not the lowest price. Viton® is simply a brand name for FKM — technically it's the same family of fluoroelastomers.

Chemically, FKM has excellent resistance to mineral oils, fuels, many acids, aliphatic and aromatic hydrocarbons and many chlorinated solvents, and it copes well with synthetic ester lubricating oils too; it is not suitable, however, for ketones (acetone, MEK), low-molecular-weight esters (ethyl acetate) or ethers. It also excels in resistance to ozone, UV and weathering, so it handles the outdoor environment as well. Thanks to this combination of thermal and chemical resistance, FKM is the standard in the chemical industry, in engines and in fuel systems, but also in aerospace and semiconductor applications — wherever a seal has to resist heat and the medium at the same time. It also has very low gas permeability, which you'll appreciate in vacuum and gas technology.

Watch the limits, though. An FKM O-ring isn't suitable for steam and hot water, for strong bases and amines (for those, reach for FEPM/Aflas), for glycol-based brake fluids, or below −20 °C, where the standard compound stiffens. These limitations have to be respected — this is exactly where the service life of the seal is decided. For low temperatures there are special low-temperature FKM compounds, which you can ask about.

Compared with the other materials, FKM stands above both NBR and HNBR in performance, but at a higher price; below it is EPDM (cheaper, but only for water, steam and brake fluids) and above it is FFKM (almost universal chemical resistance at an order-of-magnitude higher price). If temperature or chemical resistance is decisive for your application — and you don't need the extreme that calls for FFKM — an FKM O-ring is the right, proven choice.

Browse all O-rings across every material.

O-ring material comparison

Indicative values for a quick comparison. Temperature ranges are conservative (continuous service); for a specific medium always verify compatibility or consult a technician.

Material	Temperature range	Mineral oil	Water	Acid	Fuel	Hardness (Sh A)	Relative price (vs NBR)
NBR	-30 – 100 °C	Excellent	Limited	Avoid	Excellent	70 Sh A	1.0×
HNBR	-30 – 150 °C	Excellent	Limited	Avoid	Excellent	75 Sh A	3.0×
FKM — your selection	-20 – 200 °C	Excellent	Limited	Excellent	Excellent	75 Sh A	5.0×
FFKM	-20 – 260 °C	Excellent	Excellent	Excellent	Excellent	75 Sh A	50.0×
EPDM	-40 – 130 °C	Unsafe	Excellent	Excellent	Unsafe	70 Sh A	1.2×
VMQ	-60 – 200 °C	Avoid	Excellent	Avoid	Avoid	70 Sh A	3.5×
PU	-40 – 80 °C	Excellent	Limited	Avoid	Limited	90 Sh A	2.0×

Frequently asked questions about FKM (Fluoroelastomer / Viton®)

Is FKM the same as Viton®?

Viton® is a brand name for a fluoroelastomer (FKM) from Chemours — FKM is the general technical name for the whole family of these materials. In other words, every Viton is an FKM, but not every FKM carries the Viton brand. For most applications what matters is the type and quality of the FKM compound, not the brand itself; if you need a specific type (for example for low temperatures or bases), get in touch.

What temperature can an FKM O-ring withstand?

FKM (Viton®) works reliably in the −20 to +200 °C range and will briefly tolerate peaks of around +230 °C. It's precisely this high temperature resistance, combined with chemical resistance, that is its main strength. Mind the lower limit — below −20 °C standard FKM stiffens; for low temperatures there are special low-temperature compounds.

When is an FKM O-ring not enough, and when do you need a different material?

FKM isn't suitable for hot steam and water, for strong bases and amines (those call for FEPM/Aflas), for glycol-based brake fluids (EPDM), or below −20 °C. When you have extremely aggressive chemistry and high temperature at the same time, step up to FFKM. FKM is the choice for heat and most chemicals — but not for absolutely everything.

FKM (Viton®) — the complete O-ring material guide
FKM (Viton) handles -20 to +200 °C, hot oils, fuels and acids. When it beats NBR, where it fails, and how to pick the right grade, hardness and colour.
Read article

Products

O-ring 145×4 FKM 80 Shore A

O-ring 155×5.5 FKM 80 Shore A

O-ring 190×3 FKM 80 Shore A

O-ring 196.44×3.53 FKM 80 Shore A

O-ring 200×2 FKM 80 Shore A

O-ring 205×2 FKM 80 Shore A

O-ring 205×5 FKM 80 Shore A

O-ring 235×5 FKM 80 Shore A

O-ring 250×3 FKM 80 Shore A

O-ring 255×7 FKM 80 Shore A

O-ring 285×3 FKM 80 Shore A

O-ring 329.57×5.33 FKM 80 Shore A

O-ring 390×3 FKM 80 Shore A

O-ring 4.48×1.78 FKM 80 Shore A

O-ring 440×4 FKM 80 Shore A

O-ring 113.89×3.53 FKM 70 Shore A

O-ring 50×1.2 FKM 70 Shore A

O-ring 10.1×1.6 FKM 80 Shore A

O-ring 10.3×2.4 FKM 80 Shore A

O-ring 10.52×1.83 FKM 80 Shore A

O-ring 10.5×1.5 FKM 80 Shore A

O-ring 10.5×2.5 FKM 80 Shore A

O-ring 10.5×2.7 FKM 80 Shore A

O-ring 10.5×2 FKM 80 Shore A

Temperature and chemical compatibility

Temperature and chemical compatibility

Featured products

FKM (Fluoroelastomer / Viton®)

FKM (Fluoroelastomer / Viton®) — properties and applications

O-ring material comparison

Frequently asked questions about FKM (Fluoroelastomer / Viton®)

Related articles

FKM (Viton®) — the complete O-ring material guide