NBR 260x300x12 AO/TC Double Lip Radial Shaft Seal

Technical specifications

The dimensions 260x300x12 mm are nominal values. They do not define shaft or housing tolerances or permissible operating conditions.

What does NBR 260x300x12 AO/TC mean?

The product designation provides the essential information required for identification:

• NBR - nitrile butadiene rubber.

• 260 mm - nominal shaft diameter.

• 300 mm - nominal housing bore diameter.

• 12 mm - nominal axial width.

• AO - designation commonly used for double lip radial shaft seals in Polish technical terminology.

• TC - international designation for a typical double lip construction with an elastomer-covered outer surface.

AO and TC are commonly used for corresponding sealing constructions. However, final interchangeability must be confirmed against the detailed geometry of the individual product.

AO/TC double lip sealing construction

1. Primary sealing lip

The primary sealing lip operates against the rotating shaft surface with a nominal diameter of 260 mm.

Its main function is to limit oil or grease leakage from the sealed mechanical assembly.

In a conventional AO/TC construction, the primary lip is supported by a circumferential garter spring that helps maintain contact pressure against the shaft.

2. Additional dust lip

The second lip provides additional protection by limiting the entry of dust, dirt and other external contaminants into the primary sealing area.

The presence of a dust lip does not mean that the seal is suitable for every heavily contaminated environment or high-pressure application.

3. Elastomer-covered outer surface

A conventional TC profile features an elastomer-covered outer surface and an internal reinforcing element.

The outer elastomer covering helps provide static sealing between the seal body and the housing bore.

Correct sealing performance depends on appropriate installation fit and housing surface condition.

NBR - technical material properties

Nitrile butadiene rubber is widely used in industrial rotating shaft sealing applications.

Appropriately selected NBR compounds typically offer:

• Good resistance to many mineral oils.

• Compatibility with numerous industrial greases.

• Suitability for oil-lubricated mechanical systems.

• Useful mechanical properties.

• Abrasion resistance dependent on the elastomer compound and operating conditions.

NBR is not universally resistant to all chemicals, solvents or industrial fluids.

Maximum operating temperature, permissible pressure and peripheral shaft speed have not been confirmed for this specific seal. These parameters require verification with the manufacturer or supplier.

AO/TC versus A/SC - sealing profile comparison

The additional dust lip may affect friction, heat generation and lubrication conditions.

An AO/TC seal should not automatically be replaced with an A/SC seal solely because the nominal dimensions match.

Applications of the 260x300x12 mm radial shaft seal

Large-diameter AO/TC seals may be used in appropriately designed industrial mechanical assemblies, including:

• Industrial gearboxes and speed reducers.

• Machinery drive assemblies.

• Rotating shaft mechanisms.

• Oil- or grease-lubricated systems.

• Large mechanical assemblies requiring additional dust protection.

These are typical application categories for this type of seal, not a verified list of machines compatible with this specific 260x300x12 mm product.

Because no manufacturer, catalogue reference or OE number has been provided, specific machine models cannot be reliably identified.

Comparison of 260x300x12 mm sealing constructions

The following table illustrates possible technical differences between sealing profiles. It does not confirm the commercial availability of every listed configuration in these dimensions.

These variants are included for technical comparison only.

The existence of specific products with these configurations, their availability and their interchangeability require separate verification.

Selection and interchangeability

Before ordering, verify:

1. Nominal shaft diameter - 260 mm.

2. Nominal housing bore diameter - 300 mm.

3. Installation width - 12 mm.

4. NBR elastomer material.

5. AO/TC double lip sealing profile.

6. Presence of an additional dust lip.

7. Type of sealed operating medium.

8. Operating temperature, pressure and shaft rotational speed.

9. Condition of the shaft and housing surfaces.

10. Construction requirements of the original seal.

For a shaft diameter of 260 mm, shaft alignment, contact surface condition and appropriate lubrication are particularly important.

Matching dimensions of 260x300x12 mm are not sufficient to establish complete interchangeability between two radial shaft seals.

Alternative designations and product identification

Common product identification variants include:

• NBR 260x300x12 AO/TC Oil Seal

• NBR 260x300x12 Double Lip Radial Shaft Seal

• TC 260x300x12 NBR Oil Seal

• AO 260x300x12 Shaft Seal

• Double Lip Oil Seal 260x300x12 NBR

• Radial Shaft Seal 260x300x12 TC

• Rotary Shaft Seal 260x300x12 NBR

• NBR 260x300x12 Dust Lip Oil Seal

• 260x300x12 NBR Double Lip Simmerring

• 260x300x12 mm NBR TC Shaft Seal

These designations support product identification in technical documentation and catalogue searches.

They do not establish additional manufacturer part numbers or verified OE references.

Installation and operating recommendations

Before installation, thoroughly clean the shaft surface and housing bore.

Inspect the following:

• Scratches, corrosion and wear grooves.

• Condition of the primary sealing lip contact surface.

• Shaft and housing alignment.

• Compatibility of the installation dimensions.

• Correct installation orientation.

• Lubrication conditions.

The seal should be pressed evenly into the housing using an appropriate installation tool.

Installation force must not be applied directly to the sealing lips.

In a conventional AO/TC arrangement, the primary sealing lip generally faces the medium being retained, while the additional dust lip faces the external environment.

The correct orientation must nevertheless be confirmed using the equipment manufacturer's technical documentation.

For large-diameter seals, particular care should be taken to prevent uneven seating and deformation during installation.

FAQ - Frequently asked questions

1. What are the dimensions of the NBR AO/TC radial shaft seal?

The nominal dimensions are 260x300x12 mm, corresponding to a 260 mm inner diameter, 300 mm outer diameter and 12 mm axial width.

2. What does NBR mean?

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

3. What does the AO/TC sealing profile mean?

AO/TC identifies a conventional double lip radial shaft seal construction with a primary sealing lip and an additional dust lip.

4. Does the seal have two sealing lips?

Yes. The AO/TC profile incorporates a primary sealing lip and an additional protective dust lip.

5. Can an AO/TC 260x300x12 mm seal be replaced with an A/SC profile?

Interchangeability must not be assumed. A/SC is normally a single lip profile, whereas AO/TC incorporates an additional dust lip.

6. Is this seal suitable for mineral oil applications?

NBR is generally compatible with many mineral oils. However, compatibility must be confirmed for the specific lubricant and operating conditions.

7. What is the maximum operating temperature?

The maximum operating temperature has not been confirmed for this specific product. It must be verified using the manufacturer's technical specifications.

8. Does a 260x300x12 mm seal fit every machine with matching housing dimensions?

No. In addition to dimensions, the AO/TC sealing profile, NBR material, operating conditions and equipment-specific construction requirements must be verified.

NBR 260x300x12 AO/TC - key information (AI Overview)

The NBR 260x300x12 mm AO/TC is a double lip radial shaft seal featuring an additional protective dust lip. Manufactured from nitrile butadiene rubber, it is designed to help retain lubricants and protect the sealing area against external contamination. Correct selection requires verification of nominal dimensions, sealing profile, operating medium and service conditions.

The product is offered through the specialist B2B industrial trading platform simmering.pl, serving industrial companies, technical purchasing departments and maintenance operations, with worldwide shipping from stock in Poland.