M1x15.5 Viton O-Ring 75A Round Black - Pack of 100

In this review the M1x15.5 Viton O-Ring stands out as a no-nonsense replacement seal for technicians, hobbyists, and small shops who need chemical and heat resistance in a compact metric size. The bottom line: it is a purpose-built, economical pack of 100 O-rings that earns a recommendation when the job calls for a Viton elastomer with reliable compatibility for fuels and many solvents and a mid-range hardness that balances flexibility and durability.

Key Features

• Material: Made from Viton fluorocarbon elastomer to resist oils, fuels, and many chemicals for longer life in exposed applications.
• Temperature range: Rated for wide service temperatures so it can be used from cold starts up to high-heat environments without immediate failure.
• Durometer hardness: 75A hardness gives a good compromise of elasticity and compression resistance for repeated sealing cycles.
• Geometry: Round cross-section forms a reliable seal between overlapping cylindrical parts such as grooves, threads, and mating barrels.
• Pack quantity: Supplied as a pack of 100 which keeps replacement on hand and reduces downtime for maintenance tasks.

Who It's For

This O-ring is best for mechanics, maintenance technicians, and DIYers working on hydraulic fittings, fuel systems, threaded barrels or carburetor seats where resistance to fuels and aromatic hydrocarbons is required. It suits projects that need many identical seals on hand, such as workshops servicing multiple assemblies.

Those who should look elsewhere include users needing compatibility with strong alkalis, ammonia gas, or glycol-based brake fluids, and anyone requiring a softer or much harder durometer than 75A for very specific sealing dynamics.

Pros & Cons

Pros

• Good chemical and fuel resistance for common hydrocarbons and non-flammable hydraulic fluids, improving service life in those environments.
• Suitable temperature range that handles high-heat applications and high vacuum conditions where other elastomers might fail.
• Pack of 100 offers clear value and reduces repeat ordering for workshops and frequent users.
• Exact metric sizing makes it easy to match to 15.5 mm ID applications such as certain threaded barrels and carburetor seats.

Cons

• Not compatible with low molecular weight organic acids, ammonia, strong alkalis, or glycol-based brake fluids, so it is not universal.
• 75A durometer may be too stiff for applications needing a softer seal or too soft where extreme extrusion resistance is required.

Specifications

Material	Viton (fluorocarbon elastomer)
Color	Black
Inner diameter (ID)	15.5 mm
Outer diameter (OD)	17.5 mm
Cross-section width	1 mm
Durometer	75A
Temperature range	-15 degrees F (-26 degrees C) to 400 degrees F (205 degrees C)

Our Verdict

The M1x15.5 Viton O-Ring in a pack of 100 is a practical, cost-effective choice for users needing reliable fuel and chemical resistance with a moderate 75A hardness. It is especially good value for routine maintenance and applications that match the listed compatibilities, though those working with incompatible chemicals should select a different material.

Frequently Asked Questions

Are these O-rings compatible with gasoline and many aromatic hydrocarbons?
Yes, Viton is suitable for gasoline and many aromatic and aliphatic hydrocarbons, making these O-rings appropriate for those fuels.

What is the usable temperature range for these O-rings?
They are usable roughly from -15 degrees F (-26 degrees C) up to 400 degrees F (205 degrees C) for typical service conditions.

Will these work for carburetor seat seals or threaded barrel protection?
Customers report good fit and sealing for certain carburetor seats and threaded barrels; the 15.5 mm ID and 1 mm cross-section suit those specific uses when material compatibility is met.