264.2x5.7 NBR 70 ShA

What is the 264.2X5.7 NBR 70 ShA O-Ring?

The 264.2X5.7 NBR 70 ShA O-Ring is a precision metric sealing ring manufactured from NBR (Nitrile Butadiene Rubber) with a hardness of 70 Shore A. Designed for reliable static and dynamic sealing, it is widely used in hydraulic systems, pneumatic equipment, industrial machinery and OEM applications. With an inside diameter of 264.2 mm and a 5.7 mm cross-section, this O-ring provides dependable sealing performance in systems operating with mineral oils, lubricating greases and many petroleum-based fluids. The 70 Shore A hardness offers an excellent balance between flexibility, durability and mechanical strength, making it the industry standard for general-purpose sealing applications.

Design and Construction

The O-ring features a precision-moulded circular cross-section engineered to create an effective seal when compressed within a properly designed groove.

Key design features include:

• Metric dimensions
• NBR (Nitrile Butadiene Rubber) material
• 70 Shore A hardness
• Round sealing profile
• Uniform elastomer structure
• Excellent resistance to mechanical wear

Its simple yet highly effective design allows it to provide reliable sealing performance across a broad range of industrial applications.

Technical Specification

Manufacturer: GRN

Product Type: Metric O-Ring

Part Number: 264.2X5.7 NBR 70 ShA

Material: NBR (Nitrile Butadiene Rubber)

Hardness: 70 Shore A

Inside Diameter: 264.2 mm

Cross Section: 5.7 mm

Profile: Round

Colour: Black

How Does an O-Ring Work?

An O-ring seals by elastic deformation.

During installation, the sealing ring is compressed between two mating surfaces inside a sealing groove. This controlled compression generates continuous contact pressure that prevents the leakage of liquids or gases.

As system pressure increases, the pressure further energizes the seal, improving sealing efficiency. This self-energizing sealing principle explains why O-rings remain the most widely used sealing components in hydraulic and pneumatic engineering.

Why Choose NBR 70 Shore A?

NBR is one of the most commonly specified sealing materials in industrial engineering because it combines durability, flexibility and excellent compatibility with petroleum-based lubricants.

Key advantages include:

• Excellent resistance to mineral oils
• Good compatibility with lubricating greases
• High mechanical strength
• Good abrasion resistance
• Cost-effective sealing solution
• Reliable long-term performance
• Industry-standard hardness for general industrial applications

Selecting the Correct O-Ring

Proper O-ring selection should consider:

• Inside diameter
• Cross-section
• Material
• Hardness
• Operating medium
• Working temperature
• System pressure
• Static or dynamic application
• Groove dimensions
• Equipment manufacturer's specifications

Selecting the correct material and dimensions is essential for maximizing sealing performance and service life.

Installation Recommendations

For reliable operation:

• Clean the sealing groove thoroughly.
• Remove burrs and sharp edges.
• Lubricate the O-ring if recommended.
• Avoid twisting during installation.
• Do not overstretch the seal.
• Inspect all sealing surfaces before assembly.

Correct installation significantly extends seal life and reduces the likelihood of leakage.

Common Causes of O-Ring Failure

Most sealing failures result from incorrect application rather than manufacturing defects.

Typical causes include:

• Incorrect material selection
• Wrong dimensions
• Mechanical damage during installation
• Excessive stretching
• Elastomer ageing
• Contaminated sealing surfaces
• Improper groove design
• Operating beyond recommended limits

Understanding these failure mechanisms helps improve equipment reliability and reduce maintenance costs.

Industrial Applications

The 264.2X5.7 NBR 70 ShA O-Ring is suitable for industrial equipment designed for this specific metric size.

Typical applications include:

• Hydraulic systems
• Pneumatic systems
• Pumps
• Valves
• Hydraulic cylinders
• Industrial machinery
• Manufacturing equipment
• Agricultural machinery
• OEM production
• MRO maintenance operations

Application suitability should always be verified according to the equipment manufacturer's technical documentation.

OEM and Industrial Maintenance

NBR O-rings are among the most frequently replaced sealing components during preventive maintenance and industrial servicing.

Routine replacement helps:

• Prevent fluid leakage
• Improve equipment reliability
• Extend component service life
• Reduce unexpected machine downtime
• Support predictive maintenance strategies

For OEM manufacturers and maintenance engineers, using the correct seal dimensions and material is essential for long-term operational reliability.

Why Engineers Choose NBR 70 Shore A O-Rings

• Industry-standard 70 Shore A hardness
• Excellent resistance to oils and greases
• Reliable static and dynamic sealing
• High mechanical durability
• Easy installation and replacement
• Standard metric dimensions
• Suitable for OEM production and industrial maintenance
• Long operational service life

Frequently Asked Questions (FAQ)

What does 70 Shore A mean?

It is the hardness rating of the NBR elastomer measured on the Shore A hardness scale.

Can this O-ring be used with mineral oils?

Yes. NBR is widely used in systems operating with mineral oils and lubricating greases.

Is this O-ring suitable for hydraulic systems?

Yes, provided the dimensions and operating conditions match the equipment manufacturer's specifications.

Can it be used for dynamic sealing?

Yes. NBR 70 Shore A O-rings are suitable for many dynamic sealing applications when properly designed and installed.

How do I select the correct O-ring?

Selection should be based on the inside diameter, cross-section, material, hardness and the operating conditions specified by the equipment manufacturer.

Where are NBR O-rings commonly used?

They are widely used in hydraulic systems, pneumatic equipment, pumps, valves, industrial machinery, manufacturing equipment and OEM applications.