GRN® 13x28x7 NBR TC - Double Lip Radial Shaft Oil Seal

Product Description

GRN® 13x28x7 NBR TC is a double lip radial shaft oil seal (Simmerring) manufactured from nitrile butadiene rubber (NBR). Its nominal dimensions are 13x28x7 mm, with an inner diameter of 13 mm, an outer diameter of 28 mm and an axial width of 7 mm. The TC sealing profile features a primary sealing lip and an additional dust exclusion lip, helping prevent lubricant leakage and limiting contamination ingress into rotating mechanical assemblies.

The oil seal is designed for installation on a shaft with a nominal diameter of 13 mm and in a housing bore with a nominal diameter of 28 mm.

Its primary function is to retain oil or grease inside mechanical equipment, while the additional dust lip helps protect the main sealing interface against dust, dirt and fine particles.

The nominal radial cross-section height is 7.5 mm, calculated from the difference between the outer and inner diameters.

NBR is widely used in sealing applications involving many mineral oils and technical lubricating greases. Compatibility with a specific operating medium, temperature and shaft speed must be verified for the intended application.

Technical Specifications - GRN® 13x28x7 NBR TC

Technical note: The identification and dimensions are based on the supplied product designation. Without a verified GRN® technical datasheet for this specific SKU, no particular elastomer hardness, operating temperature range, permissible pressure, maximum shaft surface speed or spring construction is assigned to this product.

GRN® 13x28x7 Oil Seal Dimensions

The designation 13x28x7 mm defines three essential installation dimensions:

• Shaft diameter: 13 mm.

• Housing bore diameter: 28 mm.

• Oil seal width: 7 mm.

The nominal radial cross-section height is 7.5 mm.

These are nominal dimensions. Actual shaft, housing and oil seal tolerances must be selected according to the mechanical design requirements and equipment documentation.

What Does GRN® 13x28x7 NBR TC Mean?

GRN® - Product Brand

GRN® is a brand of technical sealing components, including radial shaft oil seals and O-rings.

13x28x7 - Nominal Dimensions

The three values indicate:

• 13 mm - inner diameter d.

• 28 mm - outer diameter D.

• 7 mm - axial width b.

NBR - Nitrile Butadiene Rubber

NBR is a synthetic elastomer commonly used in sealing applications involving many mineral oils and lubricating greases.

TC - Double Lip Sealing Profile

The TC profile identifies a construction with two lips:

• A primary sealing lip.

• An additional dust exclusion lip.

Typical TC oil seals also feature a spring-loaded primary lip, internal metal reinforcement and a rubber-covered outer diameter.

The precise construction of this particular GRN® product requires confirmation from the manufacturer's technical documentation.

Construction and Operating Principle

Primary Sealing Lip

The primary sealing lip operates directly against the rotating surface of a shaft with a nominal diameter of 13 mm.

A dynamic sealing interface is formed at the contact area to reduce oil or grease leakage from the mechanical assembly.

Sealing effectiveness depends on shaft surface condition, lip geometry, lubrication, operating temperature and shaft surface speed.

Additional Dust Exclusion Lip

The secondary lip helps prevent dust, dirt and fine particles from reaching the primary sealing interface.

It provides an additional protective barrier, particularly relevant in environments exposed to contamination.

However, this lip does not automatically provide complete resistance to pressurized water or suitability for every environmental condition.

Garter Spring

Typical TC radial shaft oil seals feature a garter spring supporting the primary sealing lip and helping maintain contact with the shaft.

The presence and exact construction of the spring in the GRN® 13x28x7 NBR TC oil seal should be confirmed using the manufacturer's documentation.

Oil Seal Body

In typical TC constructions, internal metal reinforcement stabilizes the seal body, while the rubber-covered outer surface contributes to static sealing between the oil seal and housing bore.

The precise body construction of the GRN® 13x28x7 oil seal requires manufacturer confirmation.

NBR Material - Properties and Limitations

Nitrile Butadiene Rubber is one of the most commonly used elastomers in radial shaft oil seals.

Its relevant characteristics include:

• Good resistance to many mineral oils.

• Compatibility with numerous mineral oil-based lubricating greases.

• Elasticity required for dynamic shaft sealing.

• Suitability for appropriately designed rotating mechanical assemblies.

Chemical resistance depends on the formulation of the specific NBR compound and the operating medium.

Compatibility with all synthetic oils, fuels, solvents or chemicals must not be assumed solely from the NBR designation.

Similarly, permissible operating temperature depends on the elastomer compound and application conditions. Without manufacturer data, reliable temperature limits cannot be assigned to this specific oil seal.

TC Double Lip vs Single Lip Radial Shaft Oil Seals

The TC profile provides an additional dust exclusion barrier.

However, a double lip oil seal cannot automatically replace a single lip seal in every application.

Before changing the sealing design, installation space, lip positioning and lubrication requirements must be checked.

GRN® 13x28x7 Compared with Other Oil Seal Dimensions

When identifying a replacement oil seal, all three dimensions must be considered.

The dimensions in this table are provided for geometric comparison and do not confirm the availability of specific variants.

A 13x28x8 mm oil seal is 1 mm wider than a 13x28x7 mm seal. This difference may affect installation depth and the position of the sealing lip on the shaft.

A 13x35x7 mm oil seal requires a housing bore with a nominal diameter of 35 mm rather than 28 mm.

An identical shaft diameter does not guarantee full oil seal interchangeability.

Alternative Designations and Search References

Natural variations of the product designation include:

• GRN® 13x28x7 NBR TC

• 13x28x7 NBR TC GRN®

• GRN® 13x28x7 Simmerring

• GRN® 13x28x7 NBR double lip oil seal

• 13x28x7 TC radial shaft oil seal GRN®

These are alternative ways of identifying the stated product, not verified catalogue numbers from other manufacturers.

No unverified OEM references or cross-reference numbers have been assigned.

Oil Seal Selection and Interchangeability

Before purchasing, verify the following:

1. Shaft diameter: nominally 13 mm.

2. Housing bore diameter: nominally 28 mm.

3. Axial width: 7 mm.

4. Sealing profile: double lip TC.

5. Material: NBR compatible with the operating medium.

6. Shaft condition: wear, scratches, corrosion and surface roughness.

7. Rotational speed: compatibility with permissible operating conditions.

8. Temperature: actual conditions at the sealing interface.

9. Pressure: conditions inside the housing.

10. Contamination: dust, moisture and environmental exposure.

11. Construction: compatibility of the seal body and lips with equipment requirements.

Shaft Surface Speed for a 13 mm Shaft

Shaft surface speed depends on shaft diameter and rotational speed.

It can be calculated using:

Where:

• v - shaft surface speed in m/s.

• d - shaft diameter in mm.

• n - rotational speed in rpm.

For a shaft diameter of 13 mm:

These values are geometric calculations.

They do not represent verified permissible operating speeds for the GRN® 13x28x7 NBR TC oil seal.

Typical Applications of TC Double Lip Radial Shaft Oil Seals

Double lip radial shaft oil seals are used in appropriately designed rotating mechanical assemblies where lubricant retention and protection against contamination are required.

General application categories for this sealing construction include:

• Mechanical drive systems.

• Gearboxes and rotating assemblies.

• Bearing housings.

• Industrial machinery and equipment.

These are typical applications of the sealing design, not verified OEM applications of the specific GRN® 13x28x7 product.

Suitability depends on dimensions, material, operating temperature, shaft speed, operating medium and application conditions.

Installation and Operating Recommendations

Before installation, clean the shaft surface and housing bore.

Check the shaft for scratches, sharp edges or wear grooves that could damage the sealing lip.

Install the oil seal evenly using a suitable installation tool. Installation force should not be transmitted through the sealing lips.

In typical applications, the primary sealing lip should face the retained oil or grease, while the dust exclusion lip faces the external environment. The final installation orientation must follow the equipment manufacturer's instructions.

Before initial operation, ensure appropriate lubrication of the primary sealing lip contact area. For double lip constructions, lubrication requirements for the space between the lips must also be considered.

Store the oil seal in a clean, dry environment protected from direct sunlight, ozone and deformation.

Frequently Asked Questions - GRN® 13x28x7 NBR TC

1. What are the dimensions of the GRN® 13x28x7 NBR TC oil seal?

The inner diameter is 13 mm, the outer diameter is 28 mm and the axial width is 7 mm. The nominal radial cross-section height is 7.5 mm.

2. What does TC mean in the GRN® 13x28x7 oil seal designation?

TC identifies a double lip sealing profile featuring a primary sealing lip and an additional dust exclusion lip.

3. Is the GRN® 13x28x7 a double lip oil seal?

Yes. The construction features a primary sealing lip and an additional lip designed to limit dust and contamination ingress.

4. Is NBR suitable for sealing oil?

NBR offers good resistance to many mineral oils and lubricating greases. Compatibility with the specific operating medium must be verified.

5. Can a 13x28x8 oil seal replace a 13x28x7 oil seal?

Interchangeability should not be assumed. The 1 mm difference in axial width may affect installation depth and sealing lip position.

6. Is a 13x35x7 oil seal interchangeable with a 13x28x7 oil seal?

No, not as a direct dimensional replacement. Both seals have a 13 mm inner diameter, but they require different housing bore diameters.

7. Can an oil seal from another manufacturer with the same dimensions be used?

It may be suitable if the dimensions, sealing profile, material, construction and permissible operating conditions are compatible.

8. How should the GRN® 13x28x7 NBR TC oil seal be installed?

Clean the shaft and housing, inspect the contact surfaces, install the oil seal evenly, and ensure correct sealing lip orientation and lubrication.

GRN® 13x28x7 NBR TC - Key Information

GRN® 13x28x7 NBR TC is a double lip radial shaft oil seal with nominal dimensions of 13x28x7 mm, manufactured from nitrile butadiene rubber. The TC profile features a primary sealing lip and an additional dust exclusion lip. Its nominal radial cross-section height is 7.5 mm. The seal helps reduce oil and grease leakage while limiting contamination ingress.

The GRN® 13x28x7 NBR TC oil seal is offered by simmering.pl, a specialist supplier of industrial sealing components, O-rings and bearings. The company operates a warehouse in Lublin, Poland, and serves customers in Poland and international markets.