447 Viton O-Ring 75A Durometer 9 in ID - Durable Chemical Resistant

In this review the 447 Viton O-Ring is presented as a practical replacement seal for technicians, hobbyists, and maintenance crews who need a small, reliable O-ring with strong chemical and heat resistance. The review finds the pack of five best suited to applications where fuel resistance, heat tolerance, and precise fit matter, and highlights the single biggest reason to buy: this O-ring uses Viton fluorocarbon elastomer and a 75A durometer to resist fuels, aromatic and aliphatic hydrocarbons, and high temperatures where many generic elastomers would fail.

Key Features

• Material: Made of Viton fluorocarbon elastomer to provide superior resistance to fuels, oils, ozone, and many chemicals compared with standard nitrile rubber.
• Temperature range: Rated for use from -15 degrees F to 400 degrees F so it can handle high-heat engine and industrial environments without rapid degradation.
• Hardness: 75A durometer offers firm resistance to penetration and extrusion while still allowing a conforming seal on cylindrical mating surfaces.
• Geometry: Round cross-section and precise 9 in inner diameter and 9-1/2 in outer diameter dimensions give a consistent seal between overlapping cylindrical parts where proper O-ring sizing is critical.
• Chemical compatibility: Suitable for non-flammable hydraulic fuels, silicone oil, chlorinated and aromatic hydrocarbons, and high vacuum environments for broad application use.
• Pack quantity: Sold in a pack of five so replacements and spares are available for routine maintenance or multiple installations.

Who It's For

The 447 Viton O-Ring is geared toward professionals and informed hobbyists who need a resilient seal for fuel systems, hydraulic fittings, or outdoor gear exposed to heat and ozone. It is particularly useful where customers have reported fit and leak resistance in applications such as fuel bottle seals, firearm barrel seals, and silencer switchbacks.

Those who require compatibility with glycol-based brake fluids, strong alkalis, or ammonia gas should look elsewhere, as Viton is vulnerable to certain low molecular organic acids and amines. For simple low-temperature water seals where cost is the only concern, a standard elastomer may be more economical.

Pros & Cons

Pros

• Excellent chemical and fuel resistance that maintains sealing performance in high-heat conditions.
• Customers report accurate fit and reliable leak resistance in fuel bottle and firearm seal replacements.
• 75A hardness balances durability and sealing conformity for cylindrical overlap applications.

Cons

• Not compatible with glycol-based brake fluids, strong alkalis, or some amines, so it is not universal for all chemical exposures.
• Higher-cost elastomer compared with basic nitrile O-rings, which may be unnecessary for low-stress water-only uses.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Durometer (Shore)	75A
Inner diameter (ID)	9 in
Outer diameter (OD)	9-1/2 in
Cross-section width	1/4 in
Temperature range	-15 degrees F to 400 degrees F

Our Verdict

The 447 Viton O-Ring is a sensible purchase for anyone needing a durable, heat- and fuel-resistant seal in demanding applications; the pack of five offers good value for maintenance routines. It is not the best choice for fluids known to attack fluorocarbon elastomers, but for typical fuel, oil, and high-temperature uses it delivers dependable sealing performance and proven fit in common replacement roles.

Frequently Asked Questions

Is this O-ring suitable for fuel system use?
Yes, Viton is compatible with many fuels and aromatic and aliphatic hydrocarbons, making this O-ring appropriate for many fuel system seals.

What temperature range can this O-ring tolerate?
The O-ring is rated for use from -15 degrees F to 400 degrees F, covering most engine and industrial heat exposures.

Will this work with brake fluid?
No, Viton is vulnerable to glycol-based brake fluids; choose a seal specifically rated for those fluids instead.