375 Viton O-Ring 75A Durometer, 9-1/2 in ID - Pack of 5

In this review the 375 Viton O-Ring pack is judged on durability and chemical resistance for demanding sealing jobs. The bottom line: this is a small, specialized replacement pack best suited to maintenance techs and DIYers who need a heat- and fuel-resistant seal that holds up under pressure. The pack of five offers a practical mix of size and hardness, and the review finds the biggest reason to buy is Viton material performance across high temperatures and a wide range of fuels and chemicals.

Key Features

• Material: Made of Viton fluorocarbon elastomer, it provides excellent resistance to fuels, aromatic and aliphatic hydrocarbons, and many chemicals encountered in industrial use.
• Temperature range: Rated to work from -15 degrees F to 400 degrees F, offering reliable sealing in both cold storage and high-heat applications.
• Hardness: The 75A durometer gives a firm seal that resists penetration and extrusion while still conforming to mating surfaces for leak control.
• Shape and fit: Round cross-section and precise dimensions produce a predictable seal between cylindrical overlapping surfaces like fuel bottle necks and barrel seals.
• Compatibility: Compatible with non-flammable hydraulic fuels, silicone oil, trichlorethylene and many hydrocarbons, making it useful in maintenance and replacement roles.
• Standards: Manufactured to AS568A standard sizing so it matches common O-ring grooves and replacement needs.

Who It's For

This product is for mechanics, maintenance technicians, and hobbyists who need a reliable, chemically resistant O-ring for fuel systems, seals on firearms or suppressor mounts, and industrial equipment that sees heat and fuel exposure. Customers replacing seals on MSA fuel bottles or specific barrel seals will find the size and durometer match their requirements.

It is not the best choice for applications exposed to strong alkalis, ammonia gas, low molecular weight organic acids, glycol-based brake fluids, or super-heated steam; those environments may require alternate elastomers better suited to those chemistries.

Pros & Cons

Pros

• High temperature capability up to 400 degrees F ensures long life in heat-exposed seals.
• Viton material gives strong resistance to fuels and many hydrocarbons for reliable leak prevention.
• 75A durometer balances firmness and sealing ability for common cylindrical joints.
• Pack of five provides spare parts for routine maintenance or multiple replacements.

Cons

• Not resistant to certain alkalis, amines, and glycol-based brake fluids, so it is not universal for all chemical exposures.
• The specific size is narrow in application; users must verify groove dimensions before ordering.

Specifications

Our Verdict

The 375 Viton O-Ring pack is a sensible buy for anyone needing chemically resistant, heat-tolerant seals in common cylindrical applications. Its 75A hardness and AS568A sizing deliver dependable fit and leak resistance, and the pack of five offers good value for repair and maintenance tasks where Viton compatibility is required.

Frequently Asked Questions

Will this O-ring resist gasoline and diesel?
Yes, Viton is compatible with fuels and aromatic and aliphatic hydrocarbons, so it is suitable for gasoline and diesel exposure.

Can these be used in high vacuum or ozone-exposed systems?
Yes, Viton performs well in high vacuum environments and resists ozone and weathering.

Are these compatible with brake fluid or ammonia?
No, Viton is vulnerable to glycol-based brake fluids, ammonia gas, and some organic acids, so choose a different elastomer for those fluids.