.354ft (9 mm) Buna-N O-Ring Cord Stock - Durable Sealant Choice

In this review the.354' (9 mm) Buna-N O-Ring Cord Stock is evaluated for mechanics, hobbyists, and maintenance techs who need a reliable, general-purpose sealing material. The bottom line: this round cord delivers consistent fit and good chemical compatibility for petroleum and common hydraulic fluids, making it a practical replacement material for custom o-rings and repair jobs. The reviewer found it easy to cut and glue, with a firm 70A durometer that holds shape under compression while offering useful abrasion resistance.

Key Features

• Buna-N material: Offers strong resistance to petroleum, HFA, HFB and HFC fluids so it suits many hydraulic and pneumatic sealing tasks.
• 70A durometer: Provides a firm but flexible sealing surface that retains shape and resists compression set in common service conditions.
• Wide temperature range: Usable across typical workshop temperatures, covering most cold and hot applications encountered in maintenance work.
• Made in the U.S.A.: Manufacturing origin gives confidence in consistent compound and dimensional quality compared with unspecified sources.
• Available sizes and lengths: Comes in varied cross sections and lengths so custom o-rings, gaskets, and tire repair tasks can be prepared without special tooling.

Who It's For

This product is aimed at industrial maintenance crews, hydraulic and pneumatic technicians, and DIY hobbyists who need a durable seal material compatible with petroleum-based fluids and many common oils. It fits projects that require cutting and joining cord to form custom o-rings, small gaskets, or to repair rubber components like small tires.

Those who need resistance to strong solvents, acetone, esters, or long term outdoor UV exposure should look elsewhere, since Buna-N is vulnerable to ethers and ozone and is not recommended for continuous sun or ozone-exposed applications.

Pros & Cons

Pros

• Good chemical compatibility with petroleum and hydraulic fluids for broad shop use.
• Firm 70A hardness that resists compression set and holds a reliable seal after installation.
• Easy to cut and glue into custom o-rings, with customers noting excellent fit and adhesive ease.

Cons

• Not suitable for exposure to acetone, esters, or prolonged UV/ozone environments, limiting outdoor or solvent-heavy uses.

Specifications

Our Verdict

The.354' Buna-N O-Ring Cord Stock is a solid, value-minded choice for workshop and industrial sealing work where petroleum compatibility and a stable 70A hardness are required. It is particularly good for creating custom o-rings and repairs thanks to consistent dimensions and easy gluing, but avoid it for solvent-rich or UV-exposed applications.

Frequently Asked Questions

Can this cord be glued into o-rings?
Yes. Customers report the cord is easy to glue and form into rings using compatible adhesives made for nitrile rubber.

Is it safe for automotive fuel systems?
Buna-N is compatible with petroleum and many hydrocarbon fluids, making it suitable for many fuel-related seals, but always confirm with the specific fuel and operating temperature.

Will it handle outdoor exposure?
No. Buna-N is vulnerable to ozone and UV, so it is not recommended for long-term outdoor or sunlight-exposed seals.