444 Viton O-Ring 75A Durometer, 7-3/4in ID - Pack of 10

In this review the 444 Viton O-ring is presented as a practical replacement for workshops, hobbyists, and technicians who need a durable seal that resists fuels and many chemicals. The bottom line: this pack of 10 black, round-section Viton O-rings is best for applications where heat and chemical resistance matter, since the fluorocarbon construction and 75A durometer deliver a firm, long-lasting seal across a wide temperature range. For anyone fitting seals in fuel systems, suppressors, or older equipment, the emphasis here is on reliability rather than specialty compatibility.

Key Features

• Material: Made of Viton fluorocarbon elastomer to provide strong resistance to fuels, aromatic and aliphatic hydrocarbons, and many industrial chemicals.
• Temperature range: Usable from -15 degrees F to 400 degrees F so it holds up in high-heat environments and cold storage alike.
• Durometer: 75A hardness gives a balance of flexibility and resistance to penetration, helping the ring maintain a seal under compression.
• Shape and fit: Round cross-section designed to seal between cylindrical overlapping surfaces for common plumbing and mechanical joints.
• Standards: Manufactured to the AS568A size standard so it matches common O-ring grooves and replacement charts.
• Value pack: Sold as a pack of 10 which keeps spares on hand for routine maintenance and multiple installations.

Who It's For

This O-ring is aimed at mechanics, field technicians, and DIY users who need a resilient seal for fuel pumps, suppressors, bottle fittings, and other cylindrical joints exposed to fuels or elevated temperatures. It is also useful for laboratory and industrial settings where compatibility with chlorinated and aromatic hydrocarbons is required.

Those who should look elsewhere include users who need compatibility with glycol-based brake fluids, strong alkalis, amines, ammonia gas, or super-heated steam, since Viton can be vulnerable to those chemicals. Also choose a different elastomer if a softer or harder durometer is required for a specific groove design.

Pros & Cons

Pros

• Excellent heat and fuel resistance for applications up to 400 degrees F.
• Durable 75A hardness that customers report holds up under repeated use and prevents deformation.
• Fits standard AS568A grooves and common equipment like fuel bottles and barrel seals for easy replacement.

Cons

• Not compatible with certain acids, amines, alkalis, or glycol-based brake fluids, so chemical compatibility must be checked before use.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner diameter (ID)	7-3/4 in
Outer diameter (OD)	8-1/4 in
Width / cross-section	1/4 in
Durometer	75A
Temperature range	-15 degrees F to 400 degrees F

Our Verdict

The 444 Viton O-ring pack of 10 is a sensible, cost-effective choice for anyone needing a reliable seal in fuel, high-heat, or chemically exposed environments where Viton compatibility is appropriate. It offers good durability and a standard size that makes replacements straightforward, but buyers should verify chemical compatibility if their fluids include alkalis, amines, or glycol-based brake fluids.

Frequently Asked Questions

Are these O-rings suitable for fuel systems?
Yes, Viton is compatible with many fuels and aromatic or aliphatic hydrocarbons; customers commonly use them in fuel pumps and related fittings.

Do they fit standard grooves?
They are made to the AS568A size standard and should fit standard O-ring grooves for the specified dimensions.

What chemicals should be avoided?
Avoid low molecular organic acids, ammonia gas, alkalis, amines, glycol-based brake fluids, and super-heated steam, as Viton can be vulnerable to those substances.