364 Viton O-Ring 75A Durometer 6-3/4 in ID Pack of 25 - Chemical

In this review the 364 Viton O-Ring is evaluated as a practical replacement part for technicians, hobbyists, and maintenance crews who need a resilient seal that resists fuels and many chemicals. The bottom line: this pack of 25 black Viton rings is best for users who require a reliable, heat-tolerant seal across a range of applications - the single biggest reason to buy is the material's proven chemical and thermal resistance, which makes these O-rings a cost-effective substitute for more expensive OEM parts.

Key Features

• Material: Made from Viton fluorocarbon elastomer to provide strong resistance to fuels, aromatic and aliphatic hydrocarbons, and many aggressive chemicals.
• Temperature range: Usable from -15 degrees F to 400 degrees F, giving confidence for both low-temperature storage and high-heat service.
• Durometer: 75A hardness offers firm resistance to penetration while still providing an effective seal in dynamic and static applications.
• Shape and fit: Round cross-section designed to seal between cylindrical overlapping surfaces for reliable leak resistance in common plumbing and fuel systems.
• Standards: Meets Aerospace Standard AS568A sizes, ensuring consistent dimensions for common replacement needs.
• Pack size: Supplied as a pack of 25, making it an economical option for repeated maintenance or multiple installations.

Who It's For

This Viton O-ring pack is for maintenance technicians, field service personnel, and home mechanics who replace seals on fuel bottles, hydraulic fittings, or custom plumbing where fuel and heat resistance matter. It also suits PC watercooling hobbyists and anyone who needs a durable, high-temperature elastomer in bulk.

Those who should look elsewhere include users needing compatibility with glycol-based brake fluids, certain amines or strong alkalis, or super-heated steam applications, since Viton is vulnerable to those specific chemicals and conditions.

Pros & Cons

Pros

• Excellent chemical and heat resistance for fuel and aromatic hydrocarbon exposure.
• Durable 75A shore hardness that balances resilience and sealing performance.
• Pack of 25 offers strong value for replacements or multi-point servicing.
• Consistent sizing that fits common AS568A O-ring grooves used in many assemblies.

Cons

• Not compatible with low molecular organic acids, some amines, alkalis, glycol-based brake fluids, or super-heated steam, limiting use in those environments.
• The relatively firm 75A hardness may be less forgiving in very low-pressure, delicate sealing tasks that require softer compounds.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner diameter (ID)	6-3/4 in
Outer diameter (OD)	7-1/8 in
Cross-section / Width	3/16 in
Durometer	75A
Temperature range	-15 degrees F to 400 degrees F

Our Verdict

These 364 Viton O-rings are a sensible purchase for anyone needing reliable, heat- and fuel-resistant seals in bulk. They deliver strong leak resistance and durability for most fuel, hydraulic, and high-temperature uses, making the pack of 25 a cost-effective option for repairs and preventive maintenance.

Frequently Asked Questions

Are these O-rings suitable for fuel systems?
Yes, Viton is compatible with many fuels and aromatic hydrocarbons, making these rings suitable for many fuel system sealing points.

Will they withstand high temperatures?
Yes, the specified operating range extends to 400 degrees F, so they are appropriate for many high-heat applications.

Can these be used with brake fluid or alkalis?
No, Viton is vulnerable to glycol-based brake fluids, strong alkalis, and certain amines, so avoid those fluids.