O-ring 20x3 mm NBR 90 ShA

O-ring 20x3 mm NBR 90 ShA - 100 pcs

O-ring 20x3 mm NBR 90 ShA is a technical sealing ring made of nitrile rubber (NBR), with a 20 mm inside diameter, 3 mm cross-section and 90 Shore A hardness. The nominal outside diameter is 26 mm. The harder NBR 90 ShA compound is less susceptible to deformation than standard 70 ShA versions and is intended for sealing systems requiring increased elastomer hardness.

Package: 100 pcs.

Technical Specifications - O-ring 20x3 NBR 90 ShA

What Does O-ring Size 20x3 mm Mean?

The designation:

20x3 mm

defines the two principal O-ring dimensions:

20 mm - inside diameter, ID

3 mm - cross-section diameter, CS

The nominal outside diameter can be calculated as:

OD = ID + 2 x CS

Therefore:

20 mm + 2 x 3 mm = 26 mm

The nominal outside diameter of a 20x3 mm O-ring is therefore:

OD = 26 mm

NBR 90 ShA - Material and Hardness

This O-ring is manufactured from NBR, also known as nitrile rubber or nitrile butadiene rubber.

NBR is one of the most widely used elastomers for technical sealing applications. It is particularly associated with applications involving mineral oils, greases and many compatible industrial fluids.

The designation:

90 ShA

defines the elastomer hardness on the Shore A scale.

NBR 90 ShA is significantly harder and less easily deformed than the widely used NBR 70 ShA grade.

NBR 90 ShA vs NBR 70 ShA

An O-ring with 90 ShA hardness should not simply be considered a better version of a 70 ShA O-ring.

They are different hardness grades intended for different operating conditions.

NBR 90 ShA is harder and more resistant to deformation.

NBR 70 ShA is softer and more flexible, allowing it to conform more easily to mating surfaces.

The correct hardness depends on factors such as groove geometry, extrusion gap, pressure, type of movement and the requirements of the sealing system.

A 20x3 mm NBR 70 ShA O-ring should therefore not automatically be replaced with a 20x3 mm NBR 90 ShA O-ring simply because the dimensions are identical.

Characteristics of the 20x3 NBR 90 ShA O-ring

An O-ring creates a seal when it is correctly compressed within a properly designed groove.

Effective sealing depends not only on the O-ring dimensions and material but also on:

groove dimensions

O-ring compression

groove fill

extrusion gap

pressure

temperature

medium

type of movement

surface finish of mating components

For this reason, the 20x3 mm dimensions alone are not sufficient to determine whether this O-ring is suitable for a particular application.

NBR Material Resistance

Nitrile rubber is widely used in technical sealing because of its good compatibility with many mineral-based oils and greases.

Typical media for which NBR is commonly considered include:

mineral oils

lubricating greases

selected fuels and petroleum-based products

many industrial technical fluids

Chemical compatibility must always be checked for the exact medium, concentration, operating temperature and duration of exposure.

NBR is not a universal elastomer for every chemical or operating environment.

Where Are 20x3 NBR O-rings Used?

NBR O-rings are widely used as technical seals in industry, maintenance operations, hydraulic systems, pneumatic systems, machinery and equipment.

The 20x3 NBR 90 ShA O-ring can be considered for static applications and appropriately designed dynamic applications when its dimensions, material and hardness meet the requirements of the sealing system.

The 20x3 mm size should not be assigned to a specific machine, hydraulic component or other equipment without checking the relevant technical documentation.

How to Select a 20x3 mm O-ring

When selecting this O-ring, verify:

• inside diameter ID = 20 mm
• cross-section CS = 3 mm
• outside diameter OD = 26 mm
• NBR material
• 90 ShA hardness
• operating medium
• operating temperature
• pressure
• groove dimensions
• type of movement
• extrusion gap
• required O-ring compression

An O-ring with identical 20x3 mm dimensions but made from NBR 70 ShA, FKM/FPM, EPDM or VMQ can have significantly different operating characteristics.

O-ring Installation

Before installation, check that the groove and mating surfaces are clean.

The O-ring should not be pulled across sharp edges, threads or burrs that could damage the elastomer.

During installation, avoid:

cutting or scratching the O-ring surface

excessive stretching

twisting the O-ring

contact with sharp edges

contaminating the sealing surface

If an assembly lubricant is required, it must be compatible with both the NBR elastomer and the operating medium.

Package of 100 pcs - Industrial and B2B Supply

This product is supplied in a package containing:

100 O-rings

The 100-piece package is suitable for industrial companies, maintenance departments, workshops, repair services, machinery manufacturers and B2B customers that regularly use technical seals.

simmering.pl specializes in supplying O-rings and sealing technology for industrial applications.

FAQ - O-ring 20x3 NBR 90 ShA

What are the dimensions of the 20x3 O-ring?

The O-ring has a 20 mm inside diameter and a 3 mm cross-section. Its nominal outside diameter is 26 mm.

What does NBR mean?

NBR stands for nitrile rubber, a widely used elastomer for technical seals, particularly in applications involving many mineral oils and greases.

What does 90 ShA mean?

90 ShA indicates elastomer hardness measured on the Shore A scale. It is a relatively hard O-ring grade and is less susceptible to deformation than the commonly used NBR 70 ShA grade.

Is NBR 90 ShA better than NBR 70 ShA?

Not necessarily. NBR 90 ShA is harder, while NBR 70 ShA is more flexible. The correct hardness depends on pressure, extrusion gap, groove design, movement and other operating conditions.

What is the outside diameter of a 20x3 O-ring?

The nominal outside diameter is 26 mm, calculated as 20 mm + 2 x 3 mm.

Is a 20x3 NBR O-ring resistant to oil?

NBR has good compatibility with many mineral-based oils and greases. Compatibility should nevertheless be verified for the exact medium and operating temperature.

How many O-rings are included in the package?

The package contains 100 pcs of 20x3 mm NBR 90 ShA O-rings.

O-ring 20x3 NBR 90 ShA - Key Information

O-ring 20x3 mm NBR 90 ShA is a technical sealing ring with a 20 mm inside diameter, 3 mm cross-section and 26 mm nominal outside diameter. The 90 Shore A NBR compound is harder and less susceptible to deformation than NBR 70 ShA. The product is supplied in a package of 100 pcs.

Available from simmering.pl, stock in Poland with worldwide shipping.

simmering.pl supplies NBR, FKM/FPM, EPDM and VMQ O-rings and other technical seals for industry, maintenance departments, repair services and B2B customers worldwide.