Mr O-Ring 441 Viton O-Ring 7 in ID 90A Durometer - Pack of 5

In this review of the Mr O-Ring 441 Viton O-Ring, the bottom line is simple: this pack of five high-durometer Viton seals is best for technicians and hobbyists who need reliable, high-temperature resistance in petroleum, fuel and chemical environments. The reviewer found the 90A durometer construction delivers a firm, durable seal while the nominal 7 in ID and 1/4 in cross-section match common AS568 size expectations, making these o-rings an easy replacement for many hydraulic and fluid-handling applications. Built from FKM material, they stand out for chemical and heat tolerance where standard nitrile rings fail.

Key Features

• Material: The Viton FKM compound offers excellent resistance to fuels, mineral oils and many solvents, extending seal life in harsh fluids.
• Durometer: The 90A hardness provides a firmer seal that resists extrusion and deformation under pressure, useful in static and dynamic fittings.
• Temperature Range: Rated from -26C to 232C, these rings tolerate a wide span from subfreezing to very high service temperatures.
• Size Accuracy: Nominal 7 in ID with actual dimensions close to spec ensures compatibility with AS568-defined sizes for straightforward replacements.
• Pack Quantity: Sold in packs of five, offering spare parts on hand for maintenance without buying excess inventory.

Who It's For

These Mr O-Ring 441 Viton rings suit maintenance technicians, mechanics and equipment owners who work with fuels, biodiesel blends, hydraulic fluids or high-temperature components and need a robust seal that resists chemical attack. They are also useful for laboratory setups and vacuum applications where low permeability and ozone resistance matter.

Users who primarily need very soft or highly flexible seals for low-pressure, low-temperature elastomer cushions should look to lower durometer materials instead, since the 90A hardness favors durability and resistance over extreme flexibility.

Pros & Cons

Pros

• Excellent chemical and heat resistance from FKM material improves longevity in fuel and solvent environments.
• Firm 90A durometer reduces extrusion and maintains sealing pressure under load.
• Accurate actual dimensions near nominal make these straightforward replacements for AS568 sizes.

Cons

• The relatively high hardness means reduced elasticity for applications that need a softer, more conforming seal.

Specifications

Our Verdict

The Mr O-Ring 441 Viton 90A pack of five is a solid choice for anyone needing durable, heat- and chemical-resistant seals that conform to AS568 sizing. It represents good value for maintenance and repair when resistance to fuels, oils and high temperatures is required, though those needing a softer seal should consider lower durometer options.

Frequently Asked Questions

Are these o-rings compatible with gasoline and diesel?
Yes, the Viton FKM compound is designed to perform well with petroleum products, fuels and diesel blends including biodiesel.

Do the rings match AS568 standard sizes?
Yes, the rings meet AS568 size definitions with nominal 7 in ID and actual dimensions very close to the standard.

What is the usable temperature range?
The specified range is -26C (-15F) to 232C (450F), suitable for most high-temperature sealing applications.