Mr O-Ring 448 Viton O-Ring 90A Durometer, 9-1/2ft ID Pack of 5

In this review the Mr O-Ring 448 Viton O-ring is evaluated for technicians and hobbyists who need a dependable, heat- and chemical-resistant seal. The bottom line: this pack of five 90A durometer Viton rings is best for sealing applications exposed to fuels, oils, high temperatures and ozone where durability matters. The reviewer found the nominal and actual dimensions closely matched, the material handled aggressive fluids well across the specified temperature range, and the pack size is practical for repair kits and small maintenance jobs.

Key Features

• Material: FKM Viton construction delivers strong resistance to fuels, mineral oils and many organic solvents for long-lived seals.
• Durometer: The 90A hardness gives a firm sealing surface that resists extrusion while still compressing to form reliable static seals.
• Size accuracy: Nominal 9-1/2' ID and 10' OD match the listed actual dimensions closely for predictable fit in AS568 sizing systems.
• Temperature range: Rated -26C (-15F) to 232C (450F), making these o-rings suitable for high-temperature air or fluid service.
• Chemical compatibility: Performs well with petroleum fuels, diesel blends, methanol or ethanol blends, silicone oils and some strong acids in many applications.
• Pack quantity: Supplied as a pack of 5 which keeps a few spares on hand for routine maintenance or small projects.

Who It's For

The 448 Viton o-ring is aimed at maintenance technicians, small repair shops and serious DIYers who need a compact set of high-performance seals that tolerate fuel, oil and elevated temperatures. It is particularly useful where AS568-compatible sizing and a firmer 90A hardness are preferred for static sealing or parts that may see thermal cycling.

Those working exclusively with very low-temperature systems, food-grade applications requiring specific FDA-rated materials, or where softer elastomers are needed for dynamic rotary seals should consider alternative compounds tuned to those conditions.

Pros & Cons

Pros

• Excellent chemical and temperature resistance for demanding sealer environments.
• Precise actual dimensions (9.475' ID, 10.025' OD) that align with AS568 expectations for reliable fitment.
• 90A durometer provides durable, extrusion-resistant sealing in many static applications.
• Pack of 5 is convenient for small maintenance tasks and spares.

Cons

• Higher hardness may be less suitable for dynamic seals needing a softer elastomer for flexibility.
• Not described as food-grade, so not appropriate where regulatory food contact approval is required.

Specifications

Brand	Mr O-Ring
Material	Viton (FKM)
Durometer	90A
Nominal Dimensions	9-1/2' ID, 10' OD, 1/4' CS
Actual Dimensions	9.475' ID, 10.025' OD, 0.275' CS
Temperature Range	-26C (-15F) to 232C (450F)
Pack Quantity	5

Our Verdict

The Mr O-Ring 448 Viton 90A in a pack of five is a solid, value-oriented choice for anyone who needs chemically resistant, high-temperature o-rings in AS568-compatible sizes. It is recommended for repair shops and maintenance kits where durability and compatibility with fuels and oils matter, though users requiring softer or food-grade seals should look elsewhere.

Frequently Asked Questions

Are these o-rings compatible with diesel and biodiesel?
Yes. The Viton material performs well with diesel and biodiesel blends and is specified for petroleum products.

Do the listed dimensions match actual measurements?
Yes. The product lists nominal and actual values: actual 9.475' ID and 10.025' OD which closely match nominal dimensions for predictable fit.

Can these o-rings be used at very high temperatures?
They are rated to 232C (450F) and are suitable for many high-temperature air and fluid sealing applications within that range.