475 O-Ring Viton 75A 26in ID 26-1/2in OD 1/4in Width - High Heat Seal

In this review the 475 O-Ring made of brown Viton (75A durometer) is judged on durability and sealing performance for industrial and automotive use. The bottom line: this O-ring is for users who need a heat- and chemical-resistant seal that holds up to fuels and high temperatures. It is most valuable when a precise fit and compatibility with aromatic and aliphatic hydrocarbons, silicone oils, or chlorinated solvents are required. The review finds the O-ring delivers consistent fit and leak prevention for compatible applications while offering good value for routine replacement and repair.

Key Features

• Material: Viton fluorocarbon elastomer provides excellent resistance to fuels, oils, ozone, and weathering for long service life.
• Temperature range: Rated from -15 degrees F to 450 degrees F so it can be used in both cold starts and high-heat systems without rapid degradation.
• Hardness: 75A durometer balances flexibility and compressive strength for reliable sealing in dynamic and static fittings.
• Shape and sizing: Round cross-section with 26 in ID, 26-1/2 in OD and 1/4 in width gives a standardized fit for applications calling for this AS568A size.
• Chemical compatibility: Compatible with many fuels, aromatic and aliphatic hydrocarbons, silicone oil and chlorinated hydrocarbons for broad application use.
• Standards: Meets Aerospace Size Standard AS568A which simplifies replacement and cross-referencing.

Who It's For

This O-ring is aimed at technicians, mechanics, and maintenance personnel who work with fuel systems, hydraulic fittings, or equipment exposed to high temperatures and aggressive media. It is also useful for hobbyists servicing engines or garden fittings who need a reliable, standardized seal.

Those who should look elsewhere include users requiring resistance to strong alkalis, ammonia gas or low molecular organic acids, and anyone needing an exact color match to a specific brown shade or a thicker cross section than 1/4 in. For these cases, alternative elastomers or different durometers may be more suitable.

Pros & Cons

Pros

• High chemical and heat resistance from the Viton material supports long service life in demanding environments.
• The 75A durometer provides a dependable seal in both static and mildly dynamic joints without excessive compression set.
• Customers report good fit, leak prevention, and value for common engine and hose fittings, confirming practical performance.

Cons

• Viton is vulnerable to low molecular organic acids, strong alkalis and certain amines, so it is not universal for all chemical exposures.
• Some users note the rings are thinner than expected and the color may differ from an anticipated brown, which could matter for visual or thickness-sensitive applications.

Specifications

Material	Viton (fluorocarbon elastomer)
Durometer	75A
Inner Diameter (ID)	26 in
Outer Diameter (OD)	26-1/2 in
Width / Cross-section	1/4 in (round)
Temperature Range	-15 degrees F to 450 degrees F
Standards	Aerospace Size Standard AS568A

Our Verdict

The 475 Viton O-ring is a pragmatic choice for anyone needing a standardized, heat- and fuel-resistant seal at a reasonable price. It performs well in engine and plumbing contexts where compatibility with hydrocarbons and elevated temperatures matters, though users exposed to strong alkalis or acids should select a different material. Overall it offers dependable sealing, good fit, and clear value for compatible applications.

Frequently Asked Questions

Is this O-ring compatible with gasoline and diesel fuels?
Yes, Viton is compatible with many fuels and aromatic and aliphatic hydrocarbons, making it suitable for gasoline and diesel where Viton compatibility is required.

Will this size fit hydraulic or plumbing fittings?
If your application calls for an AS568A 475 size with a 26 in ID and 1/4 in cross-section, this ring will fit; verify the specific fitting dimensions before installation.

Can this O-ring be used at high temperatures continuously?
Viton can operate up to 450 degrees F, but continuous exposure at the top end shortens life compared with moderate temperatures, so consider operating conditions when selecting seal material.