268 Viton O-Ring 8-1/2 in ID 75A Pack of 25 - Chemical & Heat

In this review the 268 Viton O-Ring pack is assessed for workshop and field use where chemical and heat resistance matter. The bottom line: this pack of 25 rings is best for technicians, hobbyists, and maintenance crews who need reliable replacement seals that resist fuels, aromatic and aliphatic hydrocarbons, and high temperatures up to 400 degrees F. The reviewer found the dimensions and 75A hardness make these rings a practical, cost-effective substitute for more expensive branded parts when compatibility and durability are the priority.

Key Features

• Material: Made from Viton fluorocarbon elastomer, it offers excellent resistance to fuels, oils, and many industrial chemicals.
• Temperature range: Rated for use from -15 degrees F to 400 degrees F, so it performs across most engine and industrial temperature conditions.
• Shape and seal: Round cross-section provides a consistent seal between overlapping cylindrical surfaces to reduce leaks under pressure.
• Hardness: The 75A shore durometer balances resistance to penetration with enough elasticity for reliable compression set performance in common sealing tasks.
• Compatibility: Works with non-flammable hydraulic fuels, silicone oil, chlorinated and aromatic hydrocarbons, and is suitable for high vacuum and weathering exposure.
• Pack size: Supplied as a pack of 25, offering ample spares for routine maintenance and multiple replacement jobs.

Who It's For

This product suits maintenance technicians, plumbing and hydraulics pros, and PC watercooling or small-engine hobbyists who need replacement O-rings that tolerate heat and contact with fuels and solvents. The pack quantity and standard sizing make it convenient for shops that service multiple similar fittings.

Those who need resistance to strong alkalis, ammonia gas, glycol-based brake fluids, or super-heated steam should look for alternative elastomers, as Viton is vulnerable to those chemicals. Also, if a softer or much harder durometer is required for a specific sealing design, select a part with the appropriate hardness.

Pros & Cons

Pros

• Good chemical and fuel resistance that covers common hydrocarbons and silicone oils.
• High temperature capability to 400 degrees F makes it suitable for engine-adjacent uses.
• Pack of 25 provides value and convenience for repeated repairs.
• Customers report strong fit and leak resistance on common fittings, including MSA fuel bottles and PC watercooling fittings.

Cons

• Not compatible with low molecular weight organic acids, amines, or glycol-based brake fluids, limiting use in some automotive and industrial fluids.
• 75A hardness may be too firm for sealing on highly irregular or low-compression surfaces where a softer compound is preferable.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner Diameter	8-1/2 in
Outer Diameter	8-3/4 in
Cross-section Width	1/8 in
Durometer	75A
Temperature Range	-15 degrees F to 400 degrees F

Our Verdict

The 268 Viton O-Ring pack is a solid, pragmatic choice for professionals and hobbyists needing heat- and fuel-resistant seals at a reasonable price. It delivers reliable fit and leak resistance for common hydraulic and fuel applications, and the pack size makes it economical for routine maintenance, though users must avoid fluids that attack Viton.

Frequently Asked Questions

Are these O-rings suitable for fuel applications?
Yes, Viton is compatible with many fuels and aromatic/aliphatic hydrocarbons, making these O-rings suitable for standard fuel contact.

Will they handle high temperatures in engine environments?
Yes, they are rated to 400 degrees F, which covers many engine-adjacent and industrial temperature conditions.

Can I use these with brake fluid or ammonia?
No, Viton is vulnerable to glycol-based brake fluids and ammonia, so choose a different elastomer for those fluids.