434 Viton O-Ring 75A, 5-5/8 in ID 6-1/8 in OD - Durable Chemical Seal

Our review of the 434 Viton O-ring finds it best suited for technicians and hobbyists who need a durable, chemical-resistant seal for fuel and hydraulic applications; the single biggest reason to buy is its material performance, since the Viton (fluorocarbon elastomer) compound resists heat, fuels and many aggressive chemicals while maintaining shape at elevated temperatures. This pack of five rings delivers consistent size and fit for cylindrical overlaps, and customers who replace seals for fuel bottles, firearm components, or pneumatic fittings will appreciate the predictable behavior of the 75A durometer in service.

Key Features

• Material: Made from Viton fluorocarbon elastomer so it resists fuels, aromatic and aliphatic hydrocarbons, and many solvents for longer service life.
• Temperature range: Usable from -15 degrees F to 400 degrees F, enabling applications from cold storage to high-heat engine or exhaust-adjacent locations.
• Hardness: The 75A shore durometer offers a balance of compression resistance and elasticity for reliable sealing under moderate deformation.
• Form factor: Round cross-section designed to provide a proper seal between cylindrical overlapping surfaces commonly found in bottles, barrels, and fittings.
• Standards: Manufactured to match Aerospace Standard AS568A sizing so customers get predictable interchangeability with common O-ring applications.

Who It's For

The 434 Viton O-ring is ideal for users who require fuel and chemical resistance in moderately hot environments, such as maintenance technicians, machinists, and firearm or silencer owners replacing seals that encounter fuels or oils. The pack format suits shops that perform recurring maintenance or parts replacement.

Those who should look elsewhere include users needing compatibility with strong alkalis, ammonia gas, or glycol-based brake fluids, and anyone requiring a very soft seal below 75A durometer or specified FDA food-grade approval not stated for this compound.

Pros & Cons

Pros

• Excellent resistance to fuels and many organic solvents, making it dependable for fuel bottle and engine-adjacent seals.
• Wide usable temperature range from sub-freezing to very high heat for flexible installation options.
• Consistent sizing and fit for AS568A-equivalent applications, making replacement straightforward.
• Pack of five provides value for repeated maintenance or multiple installations.

Cons

• Not suitable for exposure to low molecular organic acids, strong alkalis, or glycol-based brake fluids where degradation may occur.
• The 75A hardness may be firmer than desirable for some very low-pressure sealing needs requiring softer compounds.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inside Diameter (ID)	5-5/8 in
Outside Diameter (OD)	6-1/8 in
Cross-section Width	1/4 in
Durometer	75A shore
Temperature Range	-15 degrees F to 400 degrees F

Our Verdict

The 434 Viton O-ring is a practical, cost-effective choice for anyone needing a reliable seal against fuels, oils and many solvents across a wide temperature range; its AS568A-equivalent sizing and 75A hardness deliver predictable fit and durability, making the five-pack a sensible buy for maintenance shops and hobbyists who perform routine replacements.

Frequently Asked Questions

Is this O-ring safe for fuel applications?
Yes. The Viton compound is compatible with many fuels and aromatic and aliphatic hydrocarbons, making it suitable for non-flammable hydraulic fuels and most fuel sealing tasks.

What environments should be avoided?
Avoid sustained exposure to low molecular organic acids, ammonia gas, strong alkalis, amines, glycol-based brake fluids, and super-heated steam, as these can degrade Viton.

Will this fit standard AS568 sizes?
Yes. The ring is made to match AS568A sizing conventions and is offered in the stated ID and OD for direct replacement in matching housings.