446 Viton O-Ring 75A Durometer 8-1/2ft ID 9ft OD - Heat and Fuel

In this review the 446 Viton O-ring is evaluated as a straightforward, workmanlike sealing solution for users who need reliable resistance to heat, fuels and many chemicals. The bottom line: this pack of ten O-rings is best for technicians, hobbyists and maintenance teams that require a durable replacement part that holds vacuum and resists common hydrocarbon fuels. The reviewer found the material and hardness combination gives predictable sealing performance in applications that match Viton compatibility, while noting a few specific chemical limitations to consider.

Key Features

• Material: Made of Viton fluorocarbon elastomer, it offers strong resistance to heat, fuels and many solvents that would degrade other rubbers.
• Temperature range: Usable from -15 degrees F to 400 degrees F, allowing the ring to perform across cold storage to high-heat operating environments.
• Durometer: The 75A hardness provides a balance of flexibility and resistance to penetration, helping maintain a seal under compression and repeated cycles.
• Shape and fit: The round cross-section and specified 8-1/2' ID and 9' OD dimensions make it suitable for cylindrical overlapping surfaces and common replacement tasks.
• Chemical compatibility: Compatible with non-flammable hydraulic fuels, silicone oil, many aromatic and aliphatic hydrocarbons, and suitable for high vacuum and ozone exposure.
• Pack quantity: Sold as a pack of 10, offering spare parts for multiple maintenance cycles or to keep on hand for field repairs.

Who It's For

This O-ring is aimed at professionals and informed DIYers who service fuel systems, hydraulic components, vacuum fittings, or plumbing that encounter hydrocarbons, silicone oils or ozone. It works well as a direct replacement where AS568A standard sizing and a 75A Viton compound are specified, and buyers using items like MSA bottles, specific firearm seals or Silencerco switches will likely find a precise fit.

Those working with low molecular weight organic acids, strong alkalis, amines, ammonia gas, glycol-based brake fluids or super-heated steam should look for alternative elastomers, since Viton is vulnerable to these media. Also, if extreme softness or very low-temperature flexibility below -15 degrees F is required, a different durometer or compound may be preferable.

Pros & Cons

Pros

• Durable under heat and fuel exposure, providing long-lasting leak resistance in compatible systems.
• Consistent 75A hardness gives good sealing without being too stiff for many assemblies.
• AS568A standard sizing makes it easy to match to existing grooves and mating parts.
• Pack of 10 offers good value for routine maintenance and multiple replacements.

Cons

• Not compatible with certain chemicals such as ammonia, amines, glycol brake fluids and strong alkalis, limiting use in some service environments.
• 75A may be too firm for applications needing a softer, more conforming seal at very low temperatures.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Hardness	75A Shore durometer
Inner diameter	8-1/2' (in)
Outer diameter	9' (in)
Cross-section (width)	1/4' (in)
Standards	Meets Aerospace Standard AS568A sizing

Our Verdict

The 446 Viton O-ring is a practical, cost-effective choice for anyone needing a fuel- and heat-resistant seal in common cylindrical assemblies; its 75A hardness and AS568A sizing make it a reliable replacement for many industrial and consumer applications. Buyers who work with incompatible chemicals or need softer low-temperature performance should choose a different compound, but for fuel systems, vacuum fittings and general maintenance this pack represents good value and dependable service.

Frequently Asked Questions

Can this O-ring be used with gasoline and propane?
Yes, Viton is compatible with many fuels including aromatic and aliphatic hydrocarbons such as gasoline and propane, making it suitable for fuel system seals within its temperature limits.

Will these O-rings withstand high operating temperatures?
Yes, the compound is rated for use up to 400 degrees F, so it handles many high-heat applications where Viton is specified.

Are there media this Viton compound should avoid?
It should not be used with low molecular organic acids, ammonia gas, alkalis, amines, glycol-based brake fluids or super-heated steam, as these can degrade the material.