442 Viton O-Ring 75A 7-1/4in ID 7-3/4in OD Pack of 5 - Durable Seal

In this review the 442 Viton O-ring pack is presented for anyone needing a heat- and chemical-resistant seal for hydraulic, fuel, or static vacuum applications. The bottom line: this is a straightforward, no-frills set of black Viton rings that deliver reliable sealing where resistance to fuels, oils and high temperatures matters most. For installers replacing worn barrel seals, fuel pump seals or fittings exposed to hydrocarbons, the 75A durometer balance and proven Viton compound are the main reasons to buy.

Key Features

• Viton construction: The fluorocarbon elastomer formulation provides strong resistance to fuels, aromatic and aliphatic hydrocarbons and many solvents so seals last longer in harsh chemical environments.
• Wide temperature range: Rated for use from -15 degrees F to 400 degrees F, allowing these rings to be used in both colder storage and high-heat operating conditions without rapid degradation.
• 75A durometer: The medium-hardness profile offers good resistance to penetration and extrusion while still compressing to form a tight seal between cylindrical surfaces.
• Round cross-section: Classic O-ring shape ensures compatible sealing between overlapping cylindrical parts such as barrels, pumps and threaded fittings.
• AS568A size compliance: Manufactured to match Aerospace Standard sizing for interchangeability with common replacement O-ring inventories.

Who It's For

This pack is best for technicians, gunsmiths, mechanics and hobbyists who need a small set of reliable replacement O-rings for fuel systems, suppressor assemblies, barrel seals, or specialized fittings. The chemical resistance makes them suitable where exposure to fuels, silicone oil and many chlorinated or aromatic solvents occurs.

Those who should look elsewhere include users who need compatibility with strong bases, ammonia gas, glycol-based brake fluids or super-heated steam, since Viton is vulnerable to those media, and users who require a much softer or much harder shore hardness than 75A.

Pros & Cons

Pros

• Good chemical and fuel resistance for long-lasting seals in contact with hydrocarbons.
• Wide operating temperature range lets the same O-ring be used across diverse environments.
• Consistent 75A hardness balances durability with sealing compression for many applications.
• Pack of five provides spares for multiple repairs or installations.

Cons

• Not compatible with low molecular organic acids, amines, strong alkalis or glycol-based brake fluid.
• Single hardness and size mean it is not a universal replacement for all sealing needs.

Specifications

Our Verdict

The 442 Viton O-ring pack is a practical, cost-effective choice for anyone needing durable seals exposed to fuels, oils and heat. It is especially good for repairs on fuel bottles, pumps and firearm barrel seals where a proven Viton compound and 75A hardness give the right balance of resilience and sealing. Buy it when chemical resistance and temperature tolerance matter; choose different compounds if you need resistance to alkalis or glycol brake fluids.

Frequently Asked Questions

Are these O-rings suitable for fuel applications?
Yes, Viton is compatible with many fuels and hydrocarbon solvents and is commonly used in fuel system seals.

What temperatures can they withstand?
They are rated for approximately -15 degrees F up to 400 degrees F.

Will they work with brake fluid?
No, Viton is vulnerable to glycol-based brake fluids and other specific chemicals, so use a compatible material for that media.