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

In this review the 427 Viton O-Ring is assessed for workshops, maintenance techs, and anyone needing reliable seals in fuel or chemical environments; the single biggest reason to buy is its material choice, Viton, which offers broad chemical and temperature resistance that keeps seals intact where ordinary elastomers fail. The reviewer found these rings especially useful as replacements for fuel bottle and barrel seals, and appreciated that a pack of ten provides spare parts for repeat service without worrying about rapid degradation when exposed to heat, fuels, or ozone.

Key Features

• Material: Made of Viton fluorocarbon elastomer for extended resistance to fuels, aromatic and aliphatic hydrocarbons, and many chemicals.
• Temperature Range: Rated for use from -15 degrees F to 400 degrees F for reliable performance across most workshop and field conditions.
• Hardness: 75A durometer provides a balance of compression resistance and flexibility to maintain a seal under load.
• Shape and Fit: Round cross-section and precise 4-3/4 in ID and 5-1/4 in OD dimensions make it suitable for overlapping cylindrical surfaces and common replacement tasks.
• Standards: Manufactured to the AS568A sizing standard so it matches established O-ring grooves and service parts.
• Pack Quantity: Sold as a pack of 10 which reduces downtime and ensures spares are available for recurring maintenance.

Who It's For

This product suits technicians, DIY mechanics, and hobbyists who need a robust replacement O-ring for petroleum fuels, hydraulic fluids that are non-flammable, or applications exposed to heat, ozone, and vacuum. It is especially helpful for those repairing fuel bottle seals, firearm component seals, and similar cylindrical joints where a reliable Viton seal is required.

It is not the best choice for systems that contact low molecular weight organic acids, ammonia gas, alkalis, or glycol-based brake fluids, and users with those specific chemical exposures should select a compatible elastomer instead.

Pros & Cons

Pros

• Excellent heat and fuel resistance thanks to Viton construction, keeping seals reliable in high-temperature service.
• Durable 75A hardness balances wear resistance with sealing ability, noted by customers for long life and leak resistance.
• Pack of 10 provides good value and on-hand spares for repeat maintenance or multiple installations.

Cons

• Not compatible with certain chemicals like low molecular organic acids, ammonia, amines, and glycol-based brake fluids, limiting its use in some systems.

Specifications

Our Verdict

The 427 Viton O-Ring is a practical, cost-effective choice for users needing durable seals in fuel, heat, and ozone-exposed applications; buy it for its material resilience, standard sizing, and the convenience of a ten-pack. Those working with incompatible chemicals such as ammonia or glycol-based brake fluids should choose a different compound, but for general industrial sealing this is good value and dependable performance.

Frequently Asked Questions

Are these O-rings suitable for fuel systems?
Yes, Viton is compatible with many fuels, aromatic and aliphatic hydrocarbons, and non-flammable hydraulic fuels as noted.

Do these match standard sizes?
Yes, they are produced to AS568A sizing and are intended to fit common O-ring grooves for the listed ID and OD.

Can they be used with brake fluid?
No, Viton is vulnerable to glycol-based brake fluids and is not recommended for those systems.