O-Ring 124x4 NBR 70 Shore A

What Is the O-Ring 124x4 NBR 70 Shore A?

The O-Ring 124x4 NBR 70 Shore A is a precision technical sealing ring manufactured from NBR (Nitrile Butadiene Rubber, Buna-N) with an inside diameter of 124 mm and a 4 mm cross section. The 70 Shore A hardness provides an excellent balance between flexibility and compression resistance, making the seal suitable for static sealing applications as well as many dynamic systems. NBR is widely used wherever reliable sealing is required in contact with mineral oils, lubricating greases and standard hydraulic fluids.

Why Choose NBR 70 Shore A?

NBR is one of the most widely used elastomers for industrial sealing applications.

Key material properties include:

• Excellent resistance to mineral oils
• Good compatibility with lubricating greases
• Good resistance to hydraulic fluids
• High abrasion resistance
• Good mechanical strength
• Low compression set
• Reliable long-term sealing performance

The 70 Shore A hardness is considered the industry standard for general-purpose hydraulic and pneumatic sealing.

Technical Specification

Material: NBR (Nitrile Butadiene Rubber, Buna-N)

Hardness: 70 Shore A

Inside Diameter: 124 mm

Cross Section: 4 mm

Profile: O-Ring

Colour: Black

Operating Temperature: Approximately -30°C to +100°C depending on the operating medium

Chemical Resistance:

• Mineral oils
• Lubricating greases
• Hydraulic fluids
• Many petroleum-based industrial fluids

Typical Applications

The O-Ring 124x4 NBR 70 Shore A is commonly used in:

• Hydraulic systems
• Pneumatic systems
• Hydraulic cylinders
• Pumps
• Valves
• Hydraulic manifolds
• Gearboxes
• Industrial machinery
• Agricultural equipment
• Construction machinery
• Industrial automation
• Manufacturing equipment
• Machine maintenance
• General industrial sealing

How Does an O-Ring Work?

An O-ring creates a seal between two mating components by compressing inside a sealing groove. The elastomer deforms under pressure, filling the clearance between the surfaces and preventing leakage.

A correctly selected O-ring helps to:

• Prevent fluid leakage
• Retain system pressure
• Protect against contamination
• Improve equipment reliability
• Extend component service life

How to Select the Correct O-Ring

Before selecting an O-ring, verify:

• Inside diameter
• Cross-section diameter
• Elastomer material
• Operating temperature
• Working fluid
• System pressure
• Groove dimensions

Proper sizing and material selection are essential for reliable sealing performance and long service life.

Why Engineers Choose NBR O-Rings

• Excellent resistance to oils and greases
• High abrasion resistance
• Standard 70 Shore A hardness
• Easy installation
• Reliable hydraulic and pneumatic sealing
• Suitable for industrial maintenance
• Proven sealing solution for a wide range of applications

Frequently Asked Questions (FAQ)

What does the size 124x4 mean?

It indicates an inside diameter of 124 mm and a 4 mm cross section.

Is NBR resistant to hydraulic oil?

Yes. NBR is specifically designed for use with most mineral oil-based hydraulic fluids and lubricating greases.

Is 70 Shore A the standard hardness?

Yes. It is the most commonly specified hardness for general industrial O-rings.

Can this O-ring be used in pneumatic systems?

Yes. NBR performs well in both hydraulic and pneumatic sealing applications.

How should NBR O-rings be stored?

Store them in a dry environment away from direct sunlight, ozone and excessive heat to preserve their sealing properties.

Where is the 124x4 O-ring commonly used?

This size is frequently installed in hydraulic equipment, industrial machinery, pumps, valves, cylinders and other mechanical systems requiring large-diameter sealing rings.