O-ring NBR 32x5 70 Shore A

Product Characteristics

The 32x5 mm NBR O-ring is a circular elastomeric sealing element with a round cross-section.

When installed in a correctly designed groove and compressed between mating surfaces, it creates a sealing interface that helps prevent fluid or gas leakage.

The NBR 70 Shore A version is commonly selected for applications involving compatible mineral oils, industrial greases and technical fluids.

Key features:

• Inside diameter: 32 mm.

• Cross-sectional diameter: 5 mm.

• Nominal outside diameter: 42 mm.

• Material: NBR nitrile butadiene rubber.

• Nominal hardness: 70 Shore A.

• Circular cross-section.

• Elastomeric construction without metal reinforcement.

• Suitable for appropriately designed static sealing applications.

• Potential use in selected dynamic applications, subject to operating conditions.

• Packaging: 100 pieces per pack.

Technical Specifications

The nominal outside diameter of 42 mm is calculated from the inside diameter and twice the cross-sectional diameter.

Actual dimensions are subject to manufacturing tolerances, which must be confirmed for the specific product if required for the application.

What Does O-ring NBR 32x5 mm 70 Shore A Mean?

Each part of the designation identifies a specific technical characteristic.

O-ring - a closed elastomeric sealing ring with a circular cross-section.

32 - nominal inside diameter of 32 mm.

5 - nominal cross-sectional diameter of 5 mm.

NBR - nitrile butadiene rubber, a synthetic elastomer widely used in industrial sealing applications.

70 Shore A - nominal elastomer hardness measured on the Shore A scale.

100 pcs - the number of sealing rings supplied in one commercial pack.

Hardness of 70 Shore A does not indicate a pressure rating of 70 bar. Hardness is a mechanical property of the elastomer, not a maximum operating pressure.

O-ring Dimensions - 32x5 mm

O-ring dimensions are generally specified using the inside diameter followed by the cross-sectional diameter.

For this product:

• Inside diameter: 32 mm.

• Cross-sectional diameter: 5 mm.

• Nominal outside diameter: 42 mm.

The nominal outside diameter is calculated as follows:

32 mm + 2 x 5 mm = 42 mm.

An O-ring measuring 32x5 mm is not identical to a 32x4 mm, 32x5.3 mm or 42x5 mm O-ring.

Changes in cross-sectional diameter affect groove filling, compression and sealing performance.

NBR Material - Properties and Chemical Resistance

NBR, or nitrile butadiene rubber, is a synthetic elastomer commonly used in industrial sealing technology.

Typical properties of appropriately formulated NBR compounds include:

• Good resistance to many mineral oils.

• Compatibility with numerous industrial greases.

• Suitability for selected hydraulic systems using mineral oil-based fluids.

• Elasticity required for effective sealing.

• Useful mechanical properties in many industrial applications.

However, NBR is not universally compatible with every chemical or operating environment.

Resistance to solvents, aggressive chemicals, ozone, prolonged ultraviolet exposure and certain brake fluids may be limited.

Chemical compatibility depends on the specific fluid, temperature, exposure duration and NBR compound formulation.

What Does 70 Shore A Hardness Mean?

Shore A hardness describes the resistance of an elastomer to indentation under a standardized test method.

A nominal hardness of 70 Shore A is commonly used for general-purpose industrial O-rings.

Hardness influences:

• The elastomer's deformation under compression.

• Contact pressure against sealing surfaces.

• Behaviour under operating pressure.

• Resistance to extrusion into clearance gaps.

• Friction in dynamic sealing applications.

However, hardness alone does not determine sealing performance.

Groove geometry, operating pressure, temperature, extrusion gap and mating surface characteristics must also be considered.

Construction and Sealing Principle

The O-ring NBR 32x5 mm 70 Shore A is a continuous elastomeric ring with a circular cross-section.

When placed in a correctly designed groove, the ring is compressed between the mating components.

This deformation creates contact pressure, allowing the seal to restrict fluid or gas movement across the sealing interface.

Effective sealing depends on:

• Correct groove dimensions.

• Appropriate cross-sectional compression.

• Suitable groove filling.

• Surface finish of mating components.

• Extrusion gap dimensions.

• Compatibility between the elastomer and the sealed medium.

• Operating temperature and pressure.

The dimensions 32x5 mm alone do not define the permissible pressure or the required groove geometry.

O-ring NBR 32x5 mm 70 Shore A vs Other Variants

O-rings with identical nominal dimensions but different materials or hardness values are not automatically interchangeable.

The correct variant must be selected according to the medium, mechanical operating conditions and equipment requirements.

Alternative Designations and References

Common dimensional and material descriptions include:

• O-ring NBR 32x5 mm 70 Shore A

• O-ring 32x5 NBR 70

• NBR O-ring 32x5 mm

• Nitrile rubber O-ring 32x5 mm

• O-ring NBR 32x5 mm 70 Shore A - 100 pcs

These are alternative descriptions of the same nominal dimensions and material characteristics, not verified manufacturer part numbers or OEM cross-references.

Selection and Interchangeability

Before ordering, verify the following:

1. Inside diameter: 32 mm.

2. Cross-sectional diameter: 5 mm.

3. Elastomer material: NBR.

4. Nominal hardness: 70 Shore A.

5. Sealing arrangement: static or dynamic.

6. Groove dimensions and tolerances.

7. Type of fluid or gas being sealed.

8. Operating temperature and pressure.

9. Clearance gap between mating components.

10. Any requirements for manufacturing tolerances, approvals or a specific rubber compound.

An O-ring should not be replaced with a different size simply because it can be stretched or compressed during installation.

Identical dimensions do not always guarantee complete interchangeability.

Typical Applications of NBR O-rings

NBR O-rings are used in a wide range of industrial sealing systems.

Typical applications for appropriately selected seals include:

• Hydraulic component connections.

• Mechanical equipment housings.

• Covers and flanges.

• Oil system connections.

• Selected pump assemblies.

• Mineral oil-lubricated mechanisms.

• Pneumatic equipment.

• Industrial machinery and maintenance systems.

These are general applications of NBR O-rings and do not constitute a verified equipment compatibility list for the specific 32x5 mm size.

Installation and Storage Guidelines

Before installation, clean the sealing groove and inspect all mating surfaces.

Recommended precautions:

• Avoid sharp edges during installation.

• Prevent cuts, twisting and excessive stretching.

• Use installation lubricants only after confirming compatibility with NBR and the sealed medium.

• Ensure that the O-ring is correctly positioned in its groove.

• Do not install damaged or permanently deformed sealing rings.

• Store in a clean, dry environment away from direct sunlight, heat sources and ozone.

For dynamic applications, additional evaluation of friction, lubrication, operating speed and elastomer wear is required.

Pack of 100 Pieces - Industrial and B2B Supply

O-ring NBR 32x5 mm 70 Shore A is supplied in packs containing 100 individual sealing rings.

This packaging format is suitable for:

• Industrial maintenance departments.

• Machinery repair services.

• Manufacturing facilities.

• Technical workshops.

• Spare parts inventories.

• Industrial distributors.

• B2B purchasing departments.

One sales unit contains 100 O-rings.

When ordering, check the number of packs required rather than treating the listed quantity as individual pieces.

Frequently Asked Questions

What are the dimensions of the O-ring NBR 32x5 mm?

The inside diameter is 32 mm, the cross-sectional diameter is 5 mm and the calculated nominal outside diameter is 42 mm.

What does NBR 70 Shore A mean?

NBR identifies the nitrile rubber material, while 70 Shore A specifies the nominal elastomer hardness.

Is this O-ring suitable for hydraulic oil?

NBR is commonly used with mineral oil-based hydraulic fluids. Compatibility with the specific fluid and operating conditions must be verified.

Can a 70 Shore A O-ring be replaced with a 90 Shore A version?

Not automatically. Increased hardness changes deformation behaviour, sealing contact pressure and performance under load.

Can the 32x5 mm NBR O-ring be used in dynamic sealing applications?

It may be considered for selected dynamic applications, but groove design, movement speed, friction, lubrication and wear resistance must be evaluated.

Is an O-ring 32x5 mm the same as 42x5 mm?

No. The first dimension normally specifies the inside diameter. An O-ring designated 42x5 mm has a different inside diameter.

How many O-rings are included in one pack?

Each pack contains 100 pieces of O-ring NBR 32x5 mm 70 Shore A.

Is this O-ring certified for food contact?

Food-contact certification cannot be established from the designation NBR 70 Shore A alone. Appropriate documentation for the specific compound and product is required.

O-ring NBR 32x5 mm 70 Shore A - Key Technical Information

O-ring NBR 32x5 mm 70 Shore A is an elastomeric sealing ring with a 32 mm inside diameter, 5 mm cross-section and 42 mm nominal outside diameter. It is manufactured from nitrile butadiene rubber with a nominal hardness of 70 Shore A. Designed for suitable industrial sealing applications, it is supplied in packs of 100 pieces.

NBR O-rings at simmering.pl

simmering.pl supplies NBR, FKM, EPDM and other industrial O-rings, alongside rotary shaft oil seals, bearings and technical sealing components.

Our product range supports industrial maintenance, machinery repair, manufacturing operations and B2B distribution.

O-ring NBR 32x5 mm 70 Shore A is offered in packs of 100 pieces.

Our warehouse is located in Lublin, Poland, with stock in Poland and worldwide shipping.