334 Viton O-Ring 75A, 2-5/8 in ID 3 in OD Pack of 100 - Durable Seal

Our review of the 334 Viton O-Ring pack finds it best suited for technicians, mechanics, and hobbyists who need chemical- and heat-resistant seals in bulk. The bottom line: this pack of 100 O-rings delivers reliably consistent dimensions and the chemical resistance expected from a fluorocarbon elastomer, making it the obvious choice when replacing worn seals in fuel systems, hydraulic fittings, or heat-exposed assemblies. The reviewer found the 75A hardness provides a good balance of compressive resilience and sealing force, and the wide temperature range is the single biggest reason to choose these O-rings for demanding environments.

Key Features

• Material: Made from Viton fluorocarbon elastomer, these O-rings resist many fuels and chemicals for longer service life.
• Temperature range: Rated approximately -15 degrees F to 400 degrees F, allowing use from cold storage to high-heat applications.
• Durometer: 75A hardness provides resistance to penetration while maintaining enough flexibility to form reliable seals.
• Shape and fit: Round cross-section and precise dimensions make them suitable as replacement O-rings for cylindrical overlapping surfaces and common fittings.
• Compatibility: Acceptable for use with non-flammable hydraulic fuels, silicone oils, aromatic and aliphatic hydrocarbons, and compatible with vacuum and ozone exposure.
• Pack size: Supplied in a pack of 100, offering value for maintenance shops and projects that require multiple replacements.

Who It's For

This pack is ideal for industrial maintenance crews, gunsmiths, and DIYers who replace O-rings in fuel pumps, barrels, and hardware exposed to heat and fuels. It is a good fit when consistency of size and chemical resistance are priorities and when buying in bulk reduces downtime and part shortages.

Those who should look elsewhere include users who need resistance to strong alkalis, ammonia gas, certain organic acids, glycol-based brake fluids, or super-heated steam, since Viton is vulnerable to those media. Also choose a different compound if extreme low-temperature flexibility below the specified range is required.

Pros & Cons

Pros

• Excellent chemical and fuel resistance for many common solvents and fuels.
• Wide operating temperature range suitable for hot and vacuum environments.
• Consistent 2-5/8 in ID and 3 in OD sizing in a large 100-piece pack for value and convenience.
• 75A durometer gives durable resistance to penetration while maintaining sealing ability.

Cons

• Not compatible with certain alkalis, amines, or glycol-based brake fluids, which limits some applications.
• 75A hardness may be stiffer than desired for very low-pressure soft-seal needs.

Specifications

Our Verdict

The 334 Viton O-Ring pack is a practical, cost-effective choice for users who need reliable sealing in fuel, heat, and chemical-exposed systems. It offers durable performance and consistent sizing for maintenance work, though users exposed to alkalis or glycol brake fluids should choose a different material. Overall, its resistance profile and bulk quantity make it good value for many industrial and hobbyist applications.

Frequently Asked Questions

Are these O-rings suitable for fuel system use?
Yes, they are compatible with many fuels and non-flammable hydraulic fluids, making them suitable for numerous fuel system applications.

Will they handle high temperatures?
Yes, Viton in this product is rated for use up to about 400 degrees F, so it performs well in high-heat environments.

Can these be used with brake fluid?
No, Viton is vulnerable to glycol-based brake fluids, so a different elastomer is recommended for brake system seals.