372 Viton O-Ring 75A Durometer, 8-3/4 in ID - Pack of 10

In this review the 372 Viton O-ring is evaluated for workshop and field use where chemical and heat resistance matter most. The bottom line: this pack of ten black, round Viton seals is aimed at technicians, mechanics, and hobbyists who need durable, fuel-resistant rings that hold up to heat. Its single biggest selling point is material performance - Viton (fluorocarbon elastomer) that tolerates a wide temperature range and many fuels and solvents, which makes it a dependable replacement or maintenance item for assemblies exposed to harsh fluids.

Key Features

• Material: Constructed from Viton for proven resistance to fuels, aromatic and aliphatic hydrocarbons, and many solvents, reducing swell and degradation in contact with those fluids.
• Temperature range: Rated from -15 degrees F to 400 degrees F so it remains stable in elevated engine or industrial temperatures while still functioning in cold conditions.
• Durometer: The 75A hardness gives a balance of elasticity and penetration resistance for static seals where moderate compression is needed.
• Shape and fit: Round cross-section designed to seal between overlapping cylindrical surfaces, providing a predictable sealing surface for shafts, housings, and closures.
• Standards: Manufactured to meet Aerospace Standard AS568A sizing expectations, simplifying replacement selection when standard sizes are required.
• Pack quantity: Supplied as a pack of 10 which is convenient for multiple repairs or routine maintenance spares.

Who It's For

This O-ring pack is best for maintenance techs, small engine repairers, and DIYers who work with fuel systems, suppressors, pumps, or containers where chemical compatibility and heat resistance matter. It suits users replacing worn seals in fuel bottles, hydraulic fittings, or equipment exposed to solvents and ozone.

Those who should look elsewhere include applications requiring long-term exposure to low molecular weight organic acids, strong alkalis, ammonia gas, amines, glycol-based brake fluids, or super-heated steam, as Viton is vulnerable to those chemicals and conditions.

Pros & Cons

Pros

• Excellent resistance to fuels and many solvents, which customers noted in pump and barrel seal uses.
• Wide operating temperature range that holds up under heat, making it suitable for engine-adjacent applications.
• 75A hardness balances durability and sealing capability for many static seals and fittings.
• Sold in a practical pack of 10, offering value for repeated maintenance tasks.

Cons

• Not suitable for environments with ammonia, certain acids, alkalis, or glycol brake fluids, limiting some automotive and chemical uses.
• As a standard Viton compound, it may be stiffer than softer elastomers for very low-pressure dynamic sealing needs.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner diameter (ID)	8-3/4 in
Outer diameter (OD)	9-1/8 in
Cross-section / width	3/16 in
Durometer	75A
Temperature range	-15 degrees F to 400 degrees F

Our Verdict

The 372 Viton O-ring pack is a practical, cost-effective choice for anyone needing reliable seals around fuels, oils, and many solvents at elevated temperatures. Its material properties and 75A hardness make it a solid replacement part for pumps, bottles, and static seals; just avoid use with chemistries known to attack Viton. For routine maintenance spares and heat-exposed applications, it represents good value.

Frequently Asked Questions

Can these O-rings be used with gasoline and diesel?
Yes; Viton is compatible with many fuels including gasoline and diesel, which is why customers report success in fuel pump and bottle applications.

Will they handle sustained high temperature?
They are rated to 400 degrees F for intermittent or sustained exposure, making them suitable for many high-temperature sealing tasks.

Are they suitable for brake fluid applications?
No; Viton is vulnerable to glycol-based brake fluids, so use a compatible elastomer for brake system seals.