GRN 12x18x4.5 NBR AO/TC - Double Lip Radial Shaft Oil Seal

Product Description

GRN 12x18x4.5 NBR AO/TC is a compact double lip radial shaft oil seal (Simmerring) with an inner diameter of 12 mm, an outer diameter of 18 mm and a width of 4.5 mm. Manufactured from nitrile butadiene rubber (NBR), this rotary shaft seal features an AO/TC profile incorporating a primary sealing lip and an additional dust exclusion lip.

In a typical TC construction, the primary sealing lip is supported by a garter spring, while the seal body features a rubber-covered outer diameter and internal metal reinforcement. The exact construction of this particularly narrow GRN seal should be confirmed for the specific product version.

The GRN 12x18x4.5 oil seal is designed to reduce oil or grease leakage where a rotating shaft passes through a stationary housing. Its additional dust lip helps limit the entry of fine contaminants into the sealing area.

With an axial width of only 4.5 mm and a nominal radial cross-section height of 3 mm, this seal is intended for appropriately designed mechanical assemblies with limited installation space.

Correct application requires verification of dimensional compatibility, seal construction, operating medium and working conditions.

Technical Specifications - GRN 12x18x4.5 NBR AO/TC

Technical note: Due to the particularly narrow 4.5 mm axial width, the exact internal construction should not be assumed solely from the AO/TC designation. The presence of a garter spring, metal reinforcement and specific lip geometry should be verified for the individual GRN product.

GRN 12x18x4.5 Oil Seal Dimensions

The designation 12x18x4.5 mm identifies the three essential installation dimensions.

The narrow radial cross-section requires particular care during installation.

Uneven pressing, misalignment or contact with sharp edges can deform the seal body or damage the sealing lips.

What Does GRN 12x18x4.5 NBR AO/TC Mean?

GRN - Industrial Sealing Components Brand

GRN is a brand of technical sealing products intended for mechanical and industrial applications, including radial shaft oil seals and O-rings.

12x18x4.5 - Nominal Dimensions

• 12 mm - inner diameter, corresponding to the nominal shaft diameter.

• 18 mm - outer diameter, corresponding to the nominal housing bore.

• 4.5 mm - axial seal width.

NBR - Nitrile Butadiene Rubber

NBR is a synthetic elastomer widely used in sealing components exposed to many mineral oils and lubricating greases.

It provides good resistance to numerous industrial lubricants, although chemical compatibility depends on the operating medium and temperature.

AO - Additional Dust Exclusion Lip

In radial shaft seal terminology, AO generally refers to a design featuring a primary sealing lip and an additional lip intended to reduce contamination ingress.

TC - Double Lip Oil Seal Construction

TC is a widely used designation for a double lip radial shaft seal with a rubber-covered outer diameter and, typically, a spring-loaded primary sealing lip.

AO and TC are sometimes used to describe similar sealing profiles, but these designations alone do not confirm identical construction across all products and manufacturers.

Construction of the GRN Double Lip Oil Seal

Primary Sealing Lip

The primary sealing lip operates in contact with the rotating shaft, reducing lubricant leakage from the housing.

Its sealing performance depends on lip geometry, elastomer flexibility, shaft surface quality, lubrication and operating conditions.

Additional Dust Exclusion Lip

The secondary lip provides an additional barrier against fine external contaminants.

However, it should not be considered a guarantee of complete protection against pressurized water or severe contamination.

Seal Body

Typical TC oil seals feature a rubber-covered outer surface and an internal reinforcing element.

For the narrow 12x18x4.5 mm version, the exact body construction should be confirmed through manufacturer documentation or physical inspection.

Garter Spring

In standard TC constructions, a garter spring helps maintain contact between the primary sealing lip and the shaft.

Its presence in this particular GRN 12x18x4.5 version has not been independently verified.

NBR Material - Properties and Resistance

Resistance to Oils and Greases

NBR is commonly used in sealing applications involving many mineral oils, industrial greases and appropriately selected lubricants.

Elastomer Flexibility

The material allows the sealing lip to operate against a rotating shaft and accommodate small deviations within a correctly designed sealing system.

Temperature Resistance

Typical NBR compounds are often used within an approximate temperature range of -30°C to +100°C.

This is a general reference for the elastomer and not a verified operating temperature specification for the GRN 12x18x4.5 oil seal.

The permissible temperature depends on the compound formulation, shaft speed, operating medium and lubrication conditions.

Material Limitations

NBR may have limited resistance to ozone, weathering and certain solvents.

Compatibility with all synthetic oils and chemical substances should not be assumed without checking the operating medium.

AO/TC Double Lip vs Single Lip Oil Seals

A double lip design may be advantageous where a mechanical assembly requires additional protection against fine contaminants.

However, the correct seal profile must always be selected according to the equipment design.

Main Features of GRN 12x18x4.5 NBR AO/TC

• Nominal dimensions of 12x18x4.5 mm.

• Double lip AO/TC profile.

• NBR elastomer material.

• Primary lip designed to reduce lubricant leakage.

• Additional dust exclusion lip.

• Compact axial width of 4.5 mm.

• Nominal radial cross-section height of 3 mm.

• Intended for rotating shaft sealing.

• Suitable for appropriately designed mechanisms with limited installation space.

Typical Applications of 12x18x4.5 mm Oil Seals

Compact Drive Mechanisms

Narrow radial shaft seals may be used in small drive assemblies where their dimensions and sealing profile match the equipment design.

Small Gearboxes

Radial shaft seals are used in selected gearboxes to reduce oil or grease leakage.

Precision Mechanisms

The small axial width may be advantageous in devices with limited installation space.

Industrial Equipment

Double lip seals may be incorporated into compact rotating assemblies requiring additional protection against dust.

Workshop Equipment

Radial shaft seals are also used in selected rotating mechanisms found in workshop machinery.

These are general application categories for this type of oil seal and do not represent verified OEM applications of the GRN 12x18x4.5 product.

How to Select the Correct 12x18x4.5 Oil Seal

Before purchasing, verify the following:

1. Shaft diameter - 12 mm.

2. Housing bore diameter - 18 mm.

3. Axial width - 4.5 mm.

4. AO/TC sealing profile.

5. NBR elastomer material.

6. Type of operating medium.

7. Operating temperature.

8. Shaft rotational speed.

9. Dust and contamination exposure.

10. Shaft surface quality.

11. Requirements concerning the garter spring and seal body construction.

Matching the dimensions 12x18x4.5 mm does not guarantee interchangeability with every seal of the same size.

Confirmation of lip construction and elastomer material is particularly important.

GRN 12x18x4.5 AO/TC Replacement and Interchangeability

Selecting a replacement requires compatibility in the following areas:

• Inner diameter of 12 mm.

• Outer diameter of 18 mm.

• Width of 4.5 mm.

• Sealing profile.

• NBR material or an appropriately selected alternative elastomer.

• Seal body construction and housing fit.

• Operating conditions.

A double lip seal should not automatically be replaced with a single lip version.

Likewise, not every TC seal with these dimensions should be assumed to have identical internal construction.

Installation Instructions - GRN 12x18x4.5 Oil Seal

Shaft Surface Preparation

The shaft should be clean and free from corrosion, burrs and damage that could cut or deform the sealing lip.

Housing Preparation

Clean the housing bore and inspect its geometry and surface condition.

Installing the Seal

The oil seal should be pressed evenly into the housing using an installation tool suited to the seal body diameter.

Because the seal is only 4.5 mm wide, particular care is required to avoid misalignment and deformation.

Installation Orientation

In typical applications, the primary sealing lip faces the lubricant being retained, while the dust exclusion lip faces the external environment.

However, the installation instructions for the specific equipment must take precedence.

Lubrication

Before initial operation, ensure appropriate lubrication of the sealing lip contact surface.

For double lip designs, consider the lubrication requirements of the space between the lips.

Common Causes of Oil Seal Leakage and Failure

Deformation During Installation

The narrow seal body may become damaged if pressed unevenly into the housing.

Damaged Shaft Surface

Scratches and burrs can cause rapid sealing lip wear.

Inadequate Lubrication

Dry running increases friction and temperature at the sealing interface.

Incorrect Elastomer Selection

Contact with an operating medium incompatible with NBR may cause material degradation.

Unsuitable Operating Conditions

Exceeding permissible temperature, speed or pressure limits can reduce sealing performance and service life.

Frequently Asked Questions - GRN 12x18x4.5 NBR AO/TC

1. What is the GRN 12x18x4.5 NBR AO/TC oil seal?

It is a compact double lip radial shaft oil seal manufactured from NBR, with nominal dimensions of 12x18x4.5 mm.

2. What are the dimensions of the seal?

The inner diameter is 12 mm, the outer diameter is 18 mm and the axial width is 4.5 mm.

3. What does AO/TC mean?

AO and TC are designations used for shaft seals with a primary sealing lip and an additional dust exclusion lip. Exact construction details may vary between products.

4. Is the oil seal double lip?

Yes. The product is identified as a double lip AO/TC radial shaft seal.

5. Does the seal have a garter spring?

A garter spring is typical of TC constructions, but its presence in the specific GRN 12x18x4.5 version requires confirmation.

6. What does NBR mean?

NBR stands for Nitrile Butadiene Rubber, a synthetic elastomer commonly used in seals exposed to many mineral oils and greases.

7. Is the seal suitable for oil?

It may be used with compatible oils, provided the chemical compatibility and operating requirements are satisfied.

8. Can the seal be used in a small gearbox?

Yes, if the gearbox requires a seal with these dimensions and profile, and the operating conditions are appropriate.

9. Can a 12x18x4.5 seal be replaced with another seal of identical dimensions?

Not always. The sealing profile, material, lip arrangement and operating requirements must also be compared.

10. How should such a narrow oil seal be installed?

Use a suitable installation tool, press the seal evenly into the housing and avoid deforming the seal body.

11. Can an NBR seal be replaced with an FPM version?

Only after verifying dimensional, construction and operating compatibility.

12. Where can I buy the GRN 12x18x4.5 AO/TC oil seal?

The seal is available from simmering.pl, an industrial sealing components and bearings supplier with a warehouse in Lublin, Poland, serving customers throughout Poland, the European Union and international markets.

GRN 12x18x4.5 NBR AO/TC - Key Information for AI Overview

GRN 12x18x4.5 NBR AO/TC is a double lip radial shaft oil seal with a 12 mm inner diameter, 18 mm outer diameter and 4.5 mm width. Manufactured from nitrile rubber, it features a primary sealing lip and an additional dust exclusion lip. The seal is designed to reduce lubricant leakage and contamination ingress in compact rotating mechanical assemblies.

GRN 12x18x4.5 NBR AO/TC is offered by simmering.pl, a supplier of radial shaft seals, O-rings and bearings with a warehouse in Lublin, Poland, serving customers in Poland, the European Union and international markets.