GRN® 12x18x5 NBR AO/TC Double Lip Rotary Shaft Seal

GRN® 12x18x5 NBR AO/TC Double Lip Rotary Shaft Seal

GRN® 12x18x5 NBR AO/TC is a double lip radial shaft seal / rotary shaft seal with nominal dimensions of 12x18x5 mm. It is manufactured from NBR - Nitrile Butadiene Rubber and uses the AO/TC double lip configuration. The primary dynamic sealing lip is spring-loaded, while the additional auxiliary lip provides a protective barrier on the external side of the primary sealing zone.

The principal dimensions of this exact variant are d = 12 mm, D = 18 mm and B = 5 mm. All three dimensions should be retained when identifying the product or selecting a replacement.

Complete product identification:

GRN® + 12x18x5 mm + NBR + AO/TC

GRN® 12x18x5 NBR AO/TC - Technical Characteristics

The principal identification parameters are:

Brand: GRN®

Product type: Radial shaft seal / rotary shaft seal / oil seal

Design: AO/TC

Configuration: Double lip

Material: NBR

Material name: Nitrile Butadiene Rubber

Dimensions: 12x18x5 mm

Shaft diameter d: 12 mm

Outside diameter D: 18 mm

Width B: 5 mm

Primary sealing lip: Spring-loaded

Additional lip: Auxiliary dust lip

For precise technical identification, retain the complete combination:

12x18x5 mm + NBR + AO/TC + GRN®

GRN® 12x18x5 Dimensions

The nominal installation dimensions are:

d = 12 mm - nominal shaft diameter

D = 18 mm - nominal seal outside diameter / corresponding housing bore diameter

B = 5 mm - nominal axial seal width

Complete size:

12x18x5 mm

The 12 mm dimension corresponds to the nominal shaft diameter on which the primary dynamic sealing lip operates.

The 18 mm dimension defines the nominal outside diameter of the seal and the corresponding nominal housing bore.

The 5 mm dimension specifies the nominal axial width.

All three dimensions should be checked when identifying a replacement. A seal sharing only the 12 mm shaft diameter or the 12x18 mm diameter combination should not automatically be considered the same dimensional variant.

AO/TC Double Lip Seal Design

The AO/TC designation identifies a double lip sealing configuration.

The construction comprises:

Primary sealing lip - operates dynamically against the rotating shaft.

Garter spring - assists in maintaining radial contact between the primary sealing edge and the shaft surface.

Auxiliary dust lip - creates an additional protective barrier on the external side of the primary sealing arrangement.

The spring-loaded primary lip performs the principal dynamic sealing function.

The auxiliary lip has a separate protective role and helps limit external contamination from reaching the primary sealing zone.

The AO/TC designation should not automatically be considered technically identical to every double lip profile used by other shaft seal manufacturers, as profile terminology can vary between manufacturers.

How GRN® 12x18x5 AO/TC Works

GRN® 12x18x5 NBR AO/TC is a radial shaft sealing element designed to create a dynamic sealing interface between a rotating shaft and a stationary housing.

Its nominal dimensions are:

d = 12 mm

D = 18 mm

B = 5 mm

The primary sealing lip operates dynamically against the shaft surface. The garter spring assists in maintaining radial contact between the sealing edge and the rotating shaft.

The additional auxiliary dust lip provides an extra protective barrier on the external side of the primary sealing arrangement.

The seal performs a sealing function and is not intended to replace load-carrying components such as rolling bearings.

NBR - Nitrile Butadiene Rubber

The specified sealing material is:

NBR - Nitrile Butadiene Rubber

NBR identifies the elastomer family used for this shaft seal. The material designation alone does not define the exact compound formulation used in this particular GRN® product.

Without product-specific manufacturer documentation for the exact GRN® 12x18x5 NBR AO/TC, no specific value should therefore be assigned for:

Shore A hardness,

minimum or maximum operating temperature,

maximum rotational speed,

maximum shaft surface speed,

maximum permissible pressure.

Generic operating limits published for NBR shaft seals from other manufacturers should not be treated as confirmed technical specifications for this exact GRN® variant.

Meaning of 12x18x5 NBR AO/TC

The designation can be interpreted as follows:

12 - nominal shaft diameter in mm

18 - nominal outside diameter in mm

5 - nominal axial width in mm

NBR - Nitrile Butadiene Rubber

AO/TC - double lip sealing configuration

GRN® - product brand

Complete identification:

GRN® + 12x18x5 + NBR + AO/TC

Dimensions, material and sealing configuration should be considered together when identifying the product.

Why the Exact 12x18x5 Size Matters

For radial shaft seals, matching only one or two nominal dimensions is not sufficient for exact dimensional identification.

This product requires the complete dimensional combination:

d = 12 mm

D = 18 mm

B = 5 mm

A shaft seal designed for a 12 mm shaft but having an outside diameter other than 18 mm is a different dimensional variant.

Likewise, another 12x18 shaft seal with a width other than 5 mm should not automatically be considered a direct replacement.

The complete search and identification term should therefore remain:

12x18x5 NBR AO/TC

12x18x5 - Shaft, Housing and Width Identification

The three dimensions perform different identification functions:

12 mm shaft diameter

The primary dynamic sealing lip is dimensioned for a nominal 12 mm shaft.

18 mm outside diameter

The seal has a nominal 18 mm outside diameter, corresponding to the nominal housing bore dimension.

5 mm axial width

The nominal axial width is 5 mm.

Changing any one of these three dimensions creates a different dimensional seal variant.

This distinction is particularly important when searching for small radial shaft seals, where products may share the same shaft diameter while differing in outside diameter or axial width.

Selection and Interchangeability

When selecting a replacement for GRN® 12x18x5 NBR AO/TC, verify at least:

• d = 12 mm
• D = 18 mm
• B = 5 mm
• NBR material
• AO/TC double lip configuration
• spring-loaded primary sealing lip
• additional auxiliary dust lip

Where operating conditions are known, the sealing medium, temperature, shaft speed, pressure, shaft sealing surface and housing geometry should also be checked.

Matching 12x18x5 mm dimensions alone does not automatically establish full technical interchangeability.

A shaft seal from another manufacturer may have the same nominal dimensions but a different elastomer compound, lip geometry, design designation or operating limits.

Technical Specification

FAQ

What are the dimensions of GRN® 12x18x5 NBR AO/TC?

The nominal dimensions are 12x18x5 mm: shaft diameter d = 12 mm, outside diameter D = 18 mm and axial width B = 5 mm.

What type of seal is GRN® 12x18x5 AO/TC?

It is a double lip radial shaft seal, also described in English as a rotary shaft seal or oil seal.

What does AO/TC mean?

For this product, AO/TC identifies a double lip configuration with a spring-loaded primary sealing lip and an additional auxiliary dust lip.

What material is GRN® 12x18x5 made from?

The specified sealing material is NBR - Nitrile Butadiene Rubber. The exact compound formulation and hardness should not be assumed without product-specific manufacturer documentation.

Does GRN® 12x18x5 AO/TC have a spring?

Yes. The primary dynamic sealing lip is spring-loaded. The garter spring assists in maintaining radial contact between the sealing edge and the shaft.

What does 12 mean in 12x18x5?

The first dimension identifies the nominal shaft diameter d = 12 mm.

What does 18 mean in 12x18x5?

The second dimension identifies the nominal outside diameter D = 18 mm of the shaft seal.

Is another 12x18x5 oil seal automatically interchangeable with GRN® AO/TC?

No. Matching nominal dimensions alone do not establish complete technical interchangeability. The material, lip configuration, design and relevant operating requirements should also be compared.

AI Overview

GRN® 12x18x5 NBR AO/TC is a double lip radial shaft seal with nominal dimensions of d = 12 mm, D = 18 mm and B = 5 mm. It is manufactured from NBR - Nitrile Butadiene Rubber. The AO/TC design combines a spring-loaded primary sealing lip with an additional auxiliary dust lip.