Mr O-Ring 376 Viton O-Ring 90A Durometer 9-3/4 in ID Pack of 5

In this review the Mr O-Ring 376 Viton O-Ring is assessed for workshop and industrial sealing tasks where high temperature and chemical resistance matter. The bottom line: this pack of five black, 90A durometer Viton o-rings is most useful for service technicians and maintenance professionals who need dependable seals for fuel, oil, and high-temperature applications. Its largest selling point is the material performance - Viton (FKM) that tolerates elevated temperatures and a wide range of fluids while matching common AS568 sizing for easy replacement.

Key Features

• Material: Viton (fluorocarbon rubber) offers strong resistance to high temperature and many chemicals, making these o-rings reliable in harsh environments.
• Durometer: The 90A hardness provides a firm seal that resists extrusion and deformation under pressure, useful for static and some dynamic applications.
• Dimensions: Nominal 9-3/4 in ID and 10-1/8 in OD with 3/16 in cross-section ensures compatibility with components sized to AS568 standards for straightforward replacement.
• Temperature range: Rated from -26C (-15F) to 232C (450F), these o-rings can be used in both cold startup and sustained high-temperature service without rapid deterioration.
• Chemical resistance: Performs well with petroleum fuels, diesel and biodiesel blends, mineral oils, greases, and many solvents, reducing the need for frequent part changes.
• Pack size: Supplied as a pack of five which helps fleets and maintenance shops keep spares on hand and reduce downtime.

Who It's For

These Viton o-rings are aimed at professionals maintaining engines, pumps, and hydraulic systems where exposure to fuels, oils, and heat is routine. They suit technicians replacing worn seals on flanges, connectors, or housings sized to AS568 376 dimensions who want a durable material choice over general-purpose elastomers.

Those working exclusively with aggressive fluorinated chemicals outside Viton's compatibility range or applications requiring extreme flexibility at very low temperatures should consider specialty elastomers instead. Hobbyists needing inexpensive general-purpose seals for non-critical projects might find the material cost overkill.

Pros & Cons

Pros

• Excellent high-temperature performance and long-term resistance to ozone and weather.
• Wide chemical compatibility with fuels, oils, greases, and many solvents improves durability in service.
• AS568-compatible sizing and a pack of five make replacements straightforward and economical for shops.

Cons

• Higher durometer and Viton material make these firmer and potentially less forgiving in very low-temperature or highly dynamic sealing applications.

Specifications

Material	Viton (FKM)
Durometer	90A
Nominal ID	9-3/4 in
Nominal OD	10-1/8 in
Nominal CS	3/16 in
Actual Dimensions	9.725 in ID, 10.145 in OD, 0.210 in CS
Temperature Range	-26C (-15F) to 232C (450F)

Our Verdict

The Mr O-Ring 376 Viton o-ring is a smart choice for maintenance professionals who need reliable, high-temperature seals compatible with fuels and oils; its 90A hardness and Viton chemistry offer durability and chemical resistance that justify the cost for industrial use and regular service parts stocking.

Frequently Asked Questions

Are these o-rings compatible with gasoline and diesel?
Yes, Viton is compatible with petroleum fuels, diesel and biodiesel blends, and many common automotive fluids listed in the product description.

Do the dimensions match AS568 sizing?
Yes, the product is offered to meet AS568 size standards and lists nominal and actual dimensions for verification.

How long will these o-rings last in storage?
The material has an effectively unlimited shelf-life when stored away from extreme heat and direct sunlight, per the product information.