O-ring 33x3.5 NBR 70 ShA

Technical Specifications – O-ring 33x3.5 NBR 70 ShA – 100 pcs.

The dimensions are nominal. Exact dimensional tolerances, certifications and mechanical properties depend on the specific product and manufacturer's documentation.

O-ring Dimensions – 33x3.5 mm

The nominal outside diameter is calculated as follows:

The designation 33x3.5 mm specifies the inside diameter and cross-section diameter, not the outside diameter.

When selecting the seal, dimensional tolerances and groove geometry must also be considered.

NBR Material – Nitrile Butadiene Rubber

NBR is a synthetic elastomer widely used in industrial sealing technology because of its generally good resistance to mineral oils, lubricating greases and many mineral oil-based hydraulic fluids.

Its properties depend on factors such as acrylonitrile content, compound formulation and vulcanization system.

Main Properties of NBR

• Good resistance to many mineral oils.

• Good resistance to mineral oil-based lubricating greases.

• Good resistance to many mineral hydraulic fluids.

• Suitable mechanical properties when an appropriate compound is selected.

• Generally better abrasion resistance than standard VMQ silicone compounds.

• Limited resistance to ozone and ultraviolet radiation.

• Limited suitability for prolonged exposure to many aromatic solvents.

NBR is not universally compatible with all fuels, solvents and industrial chemicals.

Hardness 70 ShA – What Does It Mean?

The designation 70 ShA indicates a nominal elastomer hardness of 70 on the Shore A scale.

This is one of the most commonly used hardness grades in industrial sealing applications.

An NBR O-ring with a hardness of 70 ShA provides a balance between flexibility, conformity to mating surfaces and resistance to deformation.

Compared with softer NBR compounds, a 70 ShA material may provide greater resistance to deformation under load.

However, actual extrusion resistance also depends on operating pressure, clearance gap, temperature and the specific compound formulation.

Operating Temperature Range

Standard NBR compounds are frequently associated with an approximate operating temperature range of -30°C to +100°C.

However, this is a general material reference and not a verified temperature specification for this particular O-ring.

Special NBR formulations may have different permissible temperature limits.

Actual suitability depends on:

• Elastomer formulation.

• Type of sealed medium.

• Exposure duration.

• Operating pressure.

• Seal compression.

• Static or dynamic operating conditions.

For critical applications, the manufacturer's material datasheet should be consulted.

Chemical Resistance of NBR 70 ShA O-rings

This table describes general NBR material characteristics rather than verified test results for the specific product.

Chemical compatibility must be assessed under the actual operating conditions.

NBR 70 ShA vs VMQ, EPDM and FKM O-rings

Elastomer selection must be based on the operating conditions.

Matching dimensions do not automatically establish material interchangeability.

Industrial Applications – O-ring 33x3.5 NBR 70 ShA – 100 pcs.

NBR O-rings may be used in appropriately designed systems, including:

• Industrial hydraulic equipment.

• Lubrication systems.

• Flanged connections.

• Covers and housings.

• Industrial valves and fittings.

• Mechanical assemblies.

• Equipment using compatible mineral oils and greases.

These are general applications of NBR materials and O-ring seals, not a manufacturer-confirmed equipment compatibility list for this specific product.

Groove Design and Seal Selection

Reliable sealing requires appropriate groove geometry and controlled O-ring compression.

Important selection factors include:

• Groove diameter.

• Groove width.

• Groove depth.

• Required compression.

• Permissible O-ring stretch.

• Extrusion clearance.

• Operating pressure.

• Chemical compatibility.

• Operating temperature.

The nominal dimensions 33x3.5 mm alone are insufficient to determine the correct groove dimensions for every application.

Installation Guidelines

• Clean the groove and mating surfaces.

• Remove sharp edges and burrs.

• Avoid excessive stretching during installation.

• Prevent twisting of the O-ring.

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

• Prevent pinching or cutting of the sealing ring.

• Check the assembled connection for leakage.

Common Causes of O-ring Leakage

Incorrect O-ring dimensions: May cause insufficient compression or installation damage.

Improper groove geometry: Can result in incorrect seal deformation.

Incompatible medium: May cause swelling, hardening or degradation of the elastomer.

Excessive pressure: Can cause extrusion into the clearance gap.

Excessive temperature: May lead to permanent deformation and loss of elasticity.

Mechanical damage: May result in cuts or tears across the sealing cross-section.

Packaging – 100 Pieces

O-ring 33x3.5 NBR 70 ShA is supplied in packages of 100 pieces.

The package quantity forms part of the commercial product identification and should be considered when placing wholesale orders, preparing maintenance kits and planning industrial component consumption.

Alternative Product Designations

• O-ring 33x3.5 NBR 70 ShA – 100 pcs.

• O-ring 33x3.5 mm NBR 70 Shore A – 100 pcs.

• O-ring 33x3.5 NBR 70 – 100 pcs.

• O-ring 33x3.5 mm NBR 70 ShA

• NBR O-ring 33x3.5 mm 70 Shore A

• Nitrile Rubber O-ring 33x3.5 mm – 100 pcs.

• Oring 33x3,5 NBR 70 ShA – 100 szt.

Alternative designation formats support product identification in technical catalogues and industrial procurement systems.

They do not establish compliance with a particular dimensional standard or material certification.

FAQ – Frequently Asked Technical Questions

What are the dimensions of O-ring 33x3.5 NBR 70 ShA – 100 pcs.?

The inside diameter is 33 mm, the cross-section diameter is 3.5 mm and the nominal outside diameter is 40 mm.

What does NBR mean?

NBR stands for nitrile butadiene rubber, a synthetic elastomer commonly used in industrial sealing applications involving compatible mineral oils and greases.

What does 70 ShA mean?

It indicates a nominal elastomer hardness of 70 on the Shore A scale.

How many O-rings are included in one package?

Each package contains 100 pieces of O-ring 33x3.5 NBR 70 ShA.

Is NBR 70 ShA resistant to hydraulic oil?

NBR generally provides good resistance to many mineral oil-based hydraulic fluids. Compatibility must be confirmed for the specific hydraulic medium.

Can this O-ring be used at high temperatures?

Standard NBR compounds are often suitable for temperatures up to approximately +100°C, but the actual limit depends on the material formulation and operating conditions.

Is NBR suitable for outdoor applications?

NBR has limited resistance to ozone, UV radiation and atmospheric ageing. Another elastomer may be more appropriate for prolonged outdoor exposure.

Can an NBR O-ring be replaced with a VMQ silicone O-ring?

Not automatically. These materials differ in chemical and mechanical properties, so replacement requires verification of the operating conditions.

Can this O-ring be used in dynamic sealing applications?

NBR may be used in appropriately designed dynamic seals. Suitability depends on movement speed, pressure, lubrication, groove geometry and surface finish.

AI Quick Answer

O-ring 33x3.5 NBR 70 ShA – 100 pcs. is an elastomeric sealing ring with a 33 mm inside diameter, 3.5 mm cross-section and 40 mm nominal outside diameter. Manufactured from nitrile butadiene rubber with a nominal hardness of 70 Shore A, it offers good resistance to many mineral oils and greases. Supplied in packages of 100 pieces.

B2B Industrial Supply – simmering.pl

O-ring 33x3.5 NBR 70 ShA – 100 pcs. is offered through simmering.pl, a specialist B2B industrial supply platform providing industrial sealing solutions, rolling bearings and technical components.

The platform serves manufacturing companies, wholesale buyers, maintenance departments, engineers and industrial procurement teams.

Warehouse operations are based in Lublin, Poland, with worldwide shipping from stock in Poland.

Technical product identification includes nominal dimensions, NBR material, 70 ShA hardness and a package quantity of 100 pieces.