474 Viton O-Ring 75A, 25 in ID 25-1/2 in OD - Durable Chemical Seal

In this review the 474 Viton O-Ring is evaluated for mechanics, HVAC technicians, and hobbyists who need a durable seal that resists heat, fuels, and many chemicals. The bottom line: this pack of 25 Viton rings stands out because the fluorocarbon compound holds up across a wide temperature range and keeps reliable leak resistance in demanding conditions. For anyone replacing seals on fuel fittings, hydraulic components, or high-temperature assemblies, the key selling point is the material performance rather than cosmetic or specialty fittings.

Key Features

• Material: Made of Viton fluorocarbon elastomer for strong resistance to fuels and many chemicals, reducing premature swell and degradation.
• Temperature range: Rated from -15 degrees F to 400 degrees F so it can be used in both cold storage and high-heat engine or exhaust environments.
• Durometer: 75A hardness offers good resistance to penetration and extrusion while maintaining a flexible seal on cylindrical surfaces.
• Cross-section: Round profile provides a dependable seal between overlapping cylindrical parts, which is the common O-ring seating geometry.
• Pack quantity: Supplied as a pack of 25, making it convenient for maintenance shops or bulk replacements without multiple orders.
• Standards: Meets the AS568A size standard so it fits typical glands and housings designed for that specification.

Who It's For

The 474 Viton O-Ring is best for technicians and DIYers who work with non-flammable hydraulic fuels, petroleum-based fluids, and applications that see elevated temperatures. It is particularly useful when a heat-resistant, fuel-resistant seal is required, such as fuel bottle fittings, certain plumbing joints, and sealed cooling loops where higher temperature tolerance is needed.

Those who should look elsewhere include users needing compatibility with strong alkalis, ammonia gas, or glycol-based brake fluids, since Viton has vulnerabilities to those chemicals. Also, if a lower hardness or a softer compound is required for very low-pressure static seals, a different durometer may be preferable.

Pros & Cons

Pros

• Excellent chemical and heat resistance for long-lasting performance in hot fuel and industrial environments.
• Consistent leak resistance and durability, reported by customers using them as replacements for fuel bottle fittings and PC watercooling.
• Good value in a pack of 25 for maintenance needs and multiple replacements.

Cons

• Not compatible with strong alkalis, certain amines, and glycol-based brake fluids, so chemical compatibility must be confirmed before use.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner diameter (ID)	25 in
Outer diameter (OD)	25-1/2 in
Cross-section/Width	1/4 in
Durometer	75A
Temperature range	-15 degrees F to 400 degrees F

Our Verdict

The 474 Viton O-Ring pack is a practical choice for anyone needing reliable, heat- and fuel-resistant seals at a reasonable bulk price. It is especially suited to repair work and routine replacement where AS568A dimensions and a 75A hardness are required. Confirm chemical compatibility for acids or alkalis, but otherwise this is a durable, cost-effective solution for industrial and hobby sealing tasks.

Frequently Asked Questions

Are these o-rings suitable for fuel applications?
Yes. The Viton compound is compatible with many fuels and aromatic hydrocarbons and provides strong resistance in fuel systems when used with compatible fluids.

What temperatures can these rings withstand?
They are usable from -15 degrees F up to 400 degrees F, making them suitable for both cold and high-temperature service.

Do these o-rings fit standard housings?
Yes. They conform to the AS568A standard size series and will fit glands designed for that specification.