NBR O-ring Cord 25.00 mm

Technical Specifications

Important: The designation 25.00 mm refers to the diameter of the cord's circular cross-section, not the inside diameter of a finished O-ring.

The supplied cord length, end joining method, and material hardness require separate confirmation.

What Does NBR O-ring Cord 25.00 mm Mean?

Unlike a finished O-ring, sealing cord does not have a predefined inside diameter.

Its designation therefore identifies the cross-section diameter and material, rather than the dimensions of a completed sealing ring.

Construction and Operating Principle

NBR O-ring Cord 25.00 mm is a continuous elastomeric profile with a solid circular cross-section.

When installed in a correctly designed sealing groove, the material undergoes controlled compression. The resulting contact pressure between the cord and mating surfaces restricts the passage of the working medium through the sealing interface.

Sealing performance depends on:

• The 25.00 mm cross-section diameter.

• Sealing groove geometry and tolerances.

• Compression of the elastomer.

• Hardness of the NBR compound.

• Condition of mating surfaces.

• Operating pressure and temperature.

• Chemical compatibility with the working medium.

• End joining method when the cord forms a closed sealing ring.

When producing a closed ring from a length of cord, the joint may have different mechanical and sealing properties from the remaining material.

A joined O-ring cord should not automatically be considered equivalent to a factory-moulded, seamless O-ring.

The performance of a joined seal depends on the joining technology, material compatibility, and operating conditions.

NBR - Nitrile Butadiene Rubber Properties

NBR is a synthetic rubber produced from acrylonitrile and butadiene. It is widely used in sealing technology because of its mechanical properties and resistance to many oil-based media.

Appropriately selected NBR compounds may provide:

• Resistance to many mineral oils.

• Resistance to selected greases and mineral oil-based hydraulic fluids.

• Elasticity suitable for static sealing applications.

• Good mechanical performance.

• Suitability for manufacturing sealing profiles with different cross-section diameters.

The chemical resistance of NBR depends partly on its acrylonitrile content and the other components of the rubber compound.

NBR may be unsuitable for contact with ketones, certain solvents, and environments requiring enhanced resistance to ozone or weathering.

No specific Shore A hardness or operating temperature range is assigned to this product without confirmed material documentation.

NBR O-ring Cord 25 mm vs Finished NBR O-ring

O-ring cord allows seals to be prepared to a required length. However, its use requires consideration of the end joining method and the sealing performance required.

A ring produced by joining sealing cord is not automatically interchangeable with a factory-moulded O-ring.

Selecting NBR O-ring Cord 25.00 mm

Before selecting this sealing cord, verify:

• Cross-section diameter: 25.00 mm.

• Material: NBR.

• Shore A hardness.

• Cross-section diameter tolerance.

• Required cord length.

• Sealing groove dimensions and tolerances.

• Required compression.

• Operating temperature.

• Operating pressure.

• Chemical compatibility with the working medium.

• Open or closed sealing configuration.

• End joining technology, where applicable.

The 25 mm cross-section is relatively large and requires a suitably designed installation space.

Sealing groove dimensions should not be selected solely from the nominal cord diameter without considering the required elastomer deformation.

Calculating Cord Length for a Closed O-ring

When manufacturing a closed sealing ring from a length of cord, the required length must be determined from the intended seal geometry.

For an ideal circular ring, without stretching or allowance for the joining process, the length measured along the centreline of the cord is:

Where:

• \(L\) - cord length measured along the cross-section centreline.

• \(D_i\) - intended inside diameter of the finished ring.

• \(d\) - cord cross-section diameter, in this case 25 mm.

This is a geometric relationship, not a complete manufacturing instruction.

The actual cutting length may require adjustment depending on the joining method, installation stretch, and dimensional requirements.

Applications of NBR O-ring Cord 25.00 mm

NBR O-ring Cord 25.00 mm may be considered for:

• Static sealing of industrial equipment housings.

• Sealing covers and large mechanical connections.

• Manufacturing sealing rings with non-standard circumferences.

• Sealing systems containing compatible mineral oils.

• Maintenance and repair applications where the equipment documentation permits the use of sealing cord.

These are potential application categories based on the profile construction and general properties of NBR, not confirmed OEM applications for this particular product.

Special care is required in high-pressure and dynamic applications, particularly where an end joint could affect sealing reliability.

Alternative Designations and Reference Formats

Natural descriptive formats include:

• NBR O-ring Cord 25.00 mm

• O-ring Cord NBR 25 mm

• NBR Round Rubber Cord 25 mm

• NBR Sealing Cord 25 mm

• Solid NBR Rubber Cord 25 mm

• Round NBR Sealing Profile 25 mm

• O-ring Cord 25 mm Nitrile Rubber

These are descriptive reference formats, not confirmed manufacturer catalogue numbers.

Installation, Handling and Storage

Before installation, inspect the cord surface, cross-section, and sealing groove.

During installation:

• Cut the cord using a suitable tool to obtain the required end geometry.

• Avoid surface cuts and mechanical damage.

• Prevent twisting of the profile.

• Ensure uniform positioning inside the groove.

• Use only assembly lubricants compatible with NBR and the working medium.

• Where end joining is necessary, use a joining technology appropriate for the sealing requirements.

NBR sealing cord should be stored in clean conditions, protected from direct sunlight, ozone, excessive heat, and mechanical deformation.

Frequently Asked Questions - FAQ

What is the diameter of NBR O-ring Cord 25.00 mm?

The nominal diameter of its circular cross-section is 25.00 mm. This is not the inside diameter of a finished O-ring.

What material is NBR O-ring Cord 25 mm made from?

It is manufactured from nitrile butadiene rubber (NBR), a synthetic elastomer commonly used in sealing systems containing compatible mineral oils.

Can NBR O-ring Cord 25 mm be used to manufacture an O-ring?

Yes, provided that a suitable end joining technology is used and the resulting sealing ring is verified for the intended application.

Is NBR sealing cord resistant to oils?

Many NBR compounds offer resistance to mineral oils and selected greases. Exact compatibility depends on the working medium and operating conditions.

What is the hardness of NBR O-ring Cord 25.00 mm?

The hardness is not specified in the product designation. A value of 70 Shore A should not be assumed without confirmation from the material specification.

Can O-ring cord be used in high-pressure applications?

Suitability cannot be confirmed from the diameter and material alone. Groove geometry, extrusion gap, hardness, and end joining method must be evaluated.

Is NBR O-ring Cord 25 mm sold by the metre?

The sales unit has not been confirmed. It is necessary to check whether the product is supplied by the metre, in predefined lengths, or in complete coils.

Can NBR O-ring cord be replaced with FKM cord?

Not automatically. Chemical compatibility, hardness, dimensions, and sealing design requirements must be compared before substitution.

NBR O-ring Cord 25.00 mm - Key Technical Information

NBR O-ring Cord 25.00 mm is a solid elastomeric sealing profile with a circular cross-section diameter of 25 mm, manufactured from nitrile butadiene rubber. It is used to prepare custom-length sealing elements. NBR is suitable for selected applications involving compatible oils and greases. Correct selection requires verification of hardness, groove geometry, chemical compatibility, and the end joining method.

NBR O-ring Cords at simmering.pl

NBR O-ring cords, O-rings, industrial sealing components, rolling bearings, and mechanical accessories are available through simmering.pl, a specialist B2B trading platform serving industrial companies, engineers, maintenance departments, and technical purchasing teams.

Our warehouse and order processing facilities are located in Lublin, Poland. We provide worldwide shipping from stock in Poland.

Technical product identification and selection assistance is available based on sealing profile dimensions, elastomer material, hardness, and application requirements.