247 Viton O-Ring 75A 4-5/8in ID 4-7/8in OD Pack of 100 - Chemical

In this review the 247 Viton O-Ring pack is judged as a practical, heavy-use sealing option for technicians, hobbyists, and maintenance crews who need reliable chemical and heat resistance without paying for specialty elastomers. The bottom line: this pack of 100 O-rings is best for people replacing common seals in fuel systems, hydraulic fittings, or high-temperature assemblies because the Viton compound and 75A hardness deliver durability and compatibility across fuels and many solvents. The reviewer found the size and fit to be consistent and the material performance to match expectations for a fluorocarbon elastomer.

Key Features

• Material: Made of Viton fluorocarbon elastomer, the compound provides strong resistance to fuels, aromatic and aliphatic hydrocarbons, and many chemicals used in industrial systems.
• Temperature range: Rated from -15 degrees F to 400 degrees F, the O-rings tolerate high operating temperatures often encountered around engines, pumps, and heated plumbing lines.
• Durometer: With a 75A hardness these O-rings resist penetration and extrusion while remaining flexible enough for static and many dynamic sealing tasks.
• Cross-section: The round cross-section forms a reliable seal between overlapping cylindrical surfaces such as shafts, bores, and threaded fittings.
• Standards: Manufactured to meet AS568A dimensions for interchangeability with common O-ring sizes found in industrial and repair parts.
• Quantity: Supplied in a pack of 100, it is convenient for shops and projects that require multiple replacements or backups.

Who It's For

This pack is aimed at mechanics, maintenance technicians, and serious DIYers who repair fuel pumps, hydraulic fittings, suppressor mounts, or other assemblies exposed to fuels, silicone oils, or chlorinated solvents. The size and AS568A compliance make it a good choice where replacing a standard O-ring quickly is necessary, or where buying in bulk reduces downtime and part hunting.

It is not the best choice for applications exposed to strong alkalis, ammonia gas, low molecular organic acids, glycol-based brake fluids, or continuous super-heated steam; those environments need alternative elastomers. Also, users needing extremely soft or extremely hard compounds outside the 75A durometer should look for different materials.

Pros & Cons

Pros

• Excellent resistance to fuels and many chemicals makes these O-rings versatile for automotive and industrial uses.
• Wide temperature tolerance supports use near engines and heated systems without rapid degradation.
• Consistent sizing and AS568A compliance mean they fit common replacement housings and equipment reliably.
• Large pack size offers good value for shops and multiple-repair scenarios.

Cons

• Not compatible with ammonia, strong alkalis, certain amines, and glycol-based brake fluids, which limits use in some specialized chemical systems.
• 75A hardness may be too firm for very low-pressure sealing or extremely delicate interfaces where a softer compound is needed.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner diameter	4-5/8 in
Outer diameter	4-7/8 in
Cross-section width	1/8 in
Durometer	75A
Temperature range	-15 degrees F to 400 degrees F

Our Verdict

For anyone who needs bulk replacement seals that stand up to heat, fuel, and many solvents, this 247 Viton O-ring pack is a sensible choice because it combines proven Viton chemistry, a useful 75A hardness, and standardized sizing for broad compatibility. It represents solid value for workshops and field technicians, provided the excluded chemicals are not part of the intended service environment.

Frequently Asked Questions

Are these O-rings suitable for fuel systems?
Yes, the Viton compound is compatible with many fuels and aromatic/aliphatic hydrocarbons, making them suitable for many fuel system seals.

Will they work at high temperatures?
Yes, they are rated to 400 degrees F, so they tolerate high-temperature applications found near engines and heated equipment.

Can these O-rings be used with brake fluid?
No, they are vulnerable to glycol-based brake fluids and should not be used where such fluids are present.