Mr O-Ring 411 Viton O-Ring 90A Durometer - Pack of 5

In this review the Mr O-Ring 411 Viton o-ring is evaluated for workshop and industrial sealing tasks where high temperature and chemical resistance matter. The bottom line: this pack of five 90A durometer Viton rings is aimed at technicians, hobbyists, and maintenance teams who need durable seals that withstand petroleum products, fuels, oils and elevated temperatures up to 232C. The reviewer found the rings reliably sized to AS568 standards and especially useful when compatibility with fuels, oils and harsh environments is the primary concern.

Key Features

• Material: Made from Viton (FKM), the o-ring offers excellent resistance to high temperatures and many solvents for dependable sealing in harsh media.
• Durometer: The 90A hardness gives a firm cross-section that holds shape under compression while still forming an effective seal in static and some dynamic applications.
• Dimensions: Nominal 2-3/4 in ID and 3-1/4 in OD with actual dimensions close to 2.725 in ID and 3.275 in OD, which matches AS568 sizing expectations for interchangeability.
• Chemical compatibility: Performs well with petroleum products, fuel blends with methanol or ethanol, diesel and biodiesel blends, mineral oils and silicone greases, reducing the need for multiple seal types.
• Temperature range: Rated from -26C (-15F) to 232C (450F), suitable for high-temperature air and many process environments where standard rubbers would fail.
• Pack quantity: Supplied as a pack of five, convenient for small repair jobs or stocking spares without excess inventory.

Who It's For

This o-ring is best for maintenance technicians, hydraulic and pneumatic specialists, and small fabrication shops that require a robust seal tolerant of fuels, oils, ozone and elevated temperatures. It is also a good choice for home mechanics replacing seals exposed to fuel or high heat.

Those who should look elsewhere include users needing very soft, low-durometer seals for delicate dynamic shafts or extreme low-temperature flexibility beyond the listed range; for those applications a different elastomer or lower durometer compound will perform better.

Pros & Cons

Pros

• High chemical and temperature resistance from the Viton (FKM) compound for long-term reliability.
• Accurate actual and nominal dimensions that conform to AS568 sizing for easy replacement.
• 90A durometer provides a firm, durable seal suitable for many static and some dynamic uses.
• Pack of five offers immediate spares for quick maintenance tasks.

Cons

• 90A hardness may be too stiff for applications needing very soft or highly elastic sealing under low compression.
• Viton is not the lowest-cost elastomer, so it may be more expensive than generic rubber options for low-demand uses.

Specifications

Material	Viton (FKM)
Durometer	90A
Nominal Dimensions	2-3/4 in ID, 3-1/4 in OD, 1/4 in CS
Actual Dimensions	2.725 in ID, 3.275 in OD, 0.275 in CS
Metric Dimensions	69.22 mm ID, 83.20 mm OD, 6.99 mm CS
Temperature Range	-26C (-15F) to 232C (450F)
Pack Quantity	5 rings

Our Verdict

The Mr O-Ring 411 Viton 90A pack of five is a practical choice for professionals and hobbyists who need a heat- and chemical-resistant seal that fits AS568 sizes. Its firm 90A hardness and reliable dimensions make it good value for sealing petrol, oils and high-temperature applications, while the pack size keeps spare parts on hand without overspending.

Frequently Asked Questions

Are these o-rings compatible with diesel and biodiesel?
Yes, the Viton compound is specified to perform well with diesel and blends with biodiesel and resists common fuel components.

Do these rings match AS568 sizes for replacements?
Yes, the product is offered to meet size standards defined by AS568, with both nominal and actual dimensions provided.

What temperature range can these o-rings handle?
The rings are rated from -26C (-15F) up to 232C (450F), suitable for many high-temperature sealing needs.