.330ft (8.4 mm) Silicone O-Ring Cord Stock 70A - Red 10 ft

Our review of the.330' (8.4 mm) Silicone O-Ring Cord Stock finds it best suited to technicians, hobbyists, and maintenance professionals who need a resilient, heat-tolerant sealing material that is easy to size and form. The single biggest reason to buy is its combination of a mid-range 70A durometer and an exceptionally wide usable temperature range, which makes this red silicone cord versatile for gaskets, custom O-rings, and repair tasks where chemical and weather resistance matter.

Key Features

• Material: Silicone construction provides reliable resistance to ozone, weather, and many oils, making it suitable for outdoor and automotive applications.
• Hardness: The 70A durometer balances flexibility and shape retention so the cord can be formed into seals that compress predictably.
• Temperature range: A very wide operating range allows use in extreme cold and high-heat environments without rapid degradation.
• Length and cross-section: Supplied as a 10 ft piece with a round cross-section, it is convenient for cutting multiple custom O-rings or continuous seals.
• Made in the U.S.A.: Domestic manufacture ensures consistent quality control and traceability for industrial use.
• Chemical compatibility: Resistant to many detergents, salt water, non-petroleum brake fluids, and certain hydraulic fluids used where fire resistance is required.

Who It's For

This cord is ideal for maintenance shops, HVAC and plumbing technicians, and DIYers who need a durable, heat-resistant sealing material that can be cut and spliced to form custom O-rings or gasket profiles. It works well where exposure to weather, ozone, or high molecular weight chlorinated aromatics is expected.

Those who require strong resistance to aromatic hydrocarbons, concentrated acids or bases, prolonged steam above 250 degrees F, or high mechanical abrasion should look at alternative elastomers; silicone is not the best choice for heavy abrasion or certain solvent exposures.

Pros & Cons

Pros

• Good balance of flexibility and firmness from the 70A durometer for consistent sealing.
• Wide usable temperature window supports extreme cold and high-heat applications.
• Broad resistance to ozone, weather, salt water, and many oils and hydraulic fluids.
• Long 10 ft length and round cross-section make it economical for multiple custom seals.

Cons

• Less resistant to mechanical abrasion and certain solvents such as benzene and trichloroethylene, so it can fail in heavy-wear or aggressive chemical environments.

Specifications

Material	Silicone
Cross-section	Round
Diameter	.330' (8.4 mm)
Durometer	70A
Length	10 ft piece
Temperature range	-76 degrees F (-60 degrees C) to 437 degrees F (225 degrees C)
Country of origin	United States

Our Verdict

The.330' silicone O-ring cord stock is a practical, cost-effective choice for users needing a heat-tolerant, weather-resistant material for custom seals and repairs. It delivers dependable performance across a wide temperature range and offers good chemical resistance for many industrial fluids, making it a strong value for general sealing tasks while users with heavy abrasion or harsh solvent exposures should consider other compounds.

Frequently Asked Questions

Can this cord be used to make custom O-rings?
Yes, the round 8.4 mm cross-section and 10 ft length are well suited for cutting and joining custom O-rings and continuous seals.

What temperatures can the silicone handle?
The material is rated for extreme temperatures roughly from -76 degrees F (-60 degrees C) up to 437 degrees F (225 degrees C).

Is this silicone resistant to oils and hydraulic fluids?
It is resistant to many engine oils, non-petroleum brake fluids, and certain hydraulic fluids, but it is vulnerable to some aromatic and chlorinated hydrocarbons and strong acids or bases.