.188 in Silicone O-Ring Cord Stock 70A - 25 ft Red

In this review of the.188 in silicone O-ring cord stock, the bottom line is simple: this red, 70A durometer cord is intended for technicians and hobbyists who need a reliable, temperature-tolerant sealing material they can cut and form on demand. The reviewer found the cord especially useful where chemical resistance and a wide service temperature range matter, and the 25 ft length makes it convenient for multiple replacement O-rings or custom seals. This review focuses on real-world utility rather than lab claims, and highlights the cord's strengths and practical limits.

Key Features

• Silicone material: Offers broad resistance to ozone, weather, detergents and many oils, making it suitable for outdoor and equipment seals.
• 70A durometer: Provides a medium firmness that balances compressibility and resilience for common static sealing tasks.
• Wide temperature range: Performs across extreme temperatures so it can be used from subfreezing applications up to high-heat environments without rapid degradation.
• Round cross-section: The standard round profile simplifies cutting and forming into replacement O-rings or custom profiles using common tools.
• 25 ft length: Supplies enough material for multiple seals or prototypes, reducing the need to source small quantities repeatedly.
• Made in USA: Domestic manufacture gives predictable material consistency and traceability for critical projects.

Who It's For

The best users are maintenance technicians, plumbing and hydraulic hobbyists, and engineers who need a flexible sealing cord that resists weather, ozone and a broad list of oils and hydraulic fluids. It is well suited to making replacement O-rings, gaskets, and custom seals where temperature extremes and chemical exposure are concerns.

This cord is not the ideal choice for high-abrasion applications or for prolonged exposure to steam above 250 degrees F, strong acids or aromatic hydrocarbons; users needing long-term wear resistance or fuel compatibility should consider alternative elastomers.

Pros & Cons

Pros

• Good overall chemical resistance for many oils and hydraulic fluids, so seals last longer in aggressive environments.
• 70A hardness gives a practical balance of flexibility and support for static seals and O-rings.
• Wide service temperature range makes it versatile across outdoor, engine, and low-temperature uses.
• Generous 25 ft length reduces waste and is convenient for multiple repairs or prototypes.

Cons

• Silicone is vulnerable to mechanical abrasion and prolonged steam exposure, so it may wear faster under friction or in high-steam environments.
• Not recommended for use with aromatic hydrocarbons or certain strong acids and bases, limiting some chemical applications.

Specifications

Material	Silicone
Cross section	Round
Thickness	0.188 in (3/16 in actual)
Durometer	70A
Length	25 ft
Temperature range	Approximately -76 F to 437 F (-60 C to 225 C)
Origin	Made in the U. S. A.

Our Verdict

The.188 in silicone O-ring cord stock is a practical, cost-effective choice for anyone needing a versatile sealing material that handles wide temperature swings and common hydraulic and oil exposures. It represents good value for general repair and prototyping work, though those needing superior abrasion resistance or compatibility with harsh aromatic solvents should look to other elastomers.

Frequently Asked Questions

Can this cord be used to make replacement O-rings?
Yes. The round cross-section and 70A hardness make it straightforward to cut and form replacement O-rings for static sealing tasks.

Is it resistant to engine oil and hydraulic fluids?
Silicone resists engine and transmission oil and many hydraulic fluids, but it is not compatible with all hydrocarbons and is vulnerable to certain aromatic and chlorinated solvents.

What temperature range will it tolerate?
The cord performs across a broad range up to the mid 400s F and down to severe cold, making it useful in both hot engine and very cold applications.