NBR 70x90x7 AO/TC Double-Lip Radial Shaft Oil Seal

NBR 70x90x7 AO/TC Double-Lip Radial Shaft Oil Seal

NBR 70x90x7 AO/TC is a double-lip radial shaft oil seal with dimensions of 70x90x7 mm. The AO/TC construction combines a spring-loaded primary sealing lip with an additional dust/protective lip. The sealing elastomer is NBR - Nitrile Butadiene Rubber.

NBR 70x90x7 AO/TC - Technical Characteristics

The principal identifying characteristics of this seal are:

Dimensions: 70x90x7 mm

Elastomer: NBR

Design: Double lip

Primary sealing lip: Spring-loaded

Additional dust/protective lip: Yes

The secondary lip is particularly important for technical identification because the same 70x90x7 mm installation dimensions are also available in single-lip configurations.

Dimensions

The principal dimensions are:

d = 70 mm - nominal shaft diameter

D = 90 mm - nominal outside diameter / housing bore

B = 7 mm - axial seal width

Complete dimensions:

70x90x7 mm

The 70 mm dimension corresponds to the nominal shaft diameter and 90 mm to the nominal housing bore.

The dimensions define the basic installation envelope but do not, by themselves, identify the complete seal construction.

Double-Lip AO/TC Construction

The AO/TC configuration incorporates two functionally different lips.

The primary sealing lip operates dynamically against the rotating shaft surface. It is supported by a garter spring, which helps maintain contact between the sealing edge and shaft.

The additional dust/protective lip is located on the air side of the seal. Its function is to provide an additional barrier between external contamination and the primary sealing area.

The secondary lip should not be interpreted as a second identical primary sealing lip. The two lips perform different functions.

How Does the 70x90x7 AO/TC Oil Seal Work?

The seal operates at the interface between:

a rotating shaft with a nominal diameter of 70 mm

and

a stationary housing with a nominal bore of 90 mm.

The spring-loaded primary lip forms the main dynamic sealing interface with the shaft.

The additional protective lip provides a secondary barrier on the external side of the seal, helping limit the ingress of dust and other contamination toward the primary sealing area.

The component therefore combines dynamic shaft sealing with additional external protection of the sealing zone.

NBR - Nitrile Butadiene Rubber

The sealing elastomer is:

NBR - Nitrile Butadiene Rubber

NBR identifies the elastomer family, not one specific compound.

Different NBR compounds can have different hardness and operating limits. For this reason, an unspecified generic NBR 70x90x7 AO/TC seal should not automatically be assigned an exact:

Shore A hardness

operating temperature range

maximum shaft speed

pressure limit

These parameters should be verified against the documentation for the actual manufacturer's compound when required for engineering selection.

What Does AO/TC Mean?

For this product, AO/TC identifies the double-lip configuration consisting of:

one spring-loaded primary sealing lip

plus

one additional dust/protective lip

Profile nomenclature varies between seal manufacturers. Corresponding double-lip constructions may therefore appear under designations such as AS, WAS, BASL or TC, depending on the manufacturer's system.

These codes should not be treated as universally interchangeable without checking the actual seal construction.

AO/TC vs A/SC

This distinction is important because both versions can have exactly the same 70x90x7 mm dimensions.

A / SC

One spring-loaded primary sealing lip.

No additional dust lip.

AO / TC

One spring-loaded primary sealing lip.

Additional dust/protective lip.

Therefore, 70x90x7 AO/TC and 70x90x7 A/SC are different seal configurations, despite having identical nominal installation dimensions.

Direction of Rotation

The designation AO/TC alone does not confirm a directional hydrodynamic structure on the primary sealing lip.

It should therefore not automatically be assigned:

RD - Right-hand

LD - Left-hand

WD - Alternating

A directional designation requires confirmation of the actual sealing-edge geometry.

Replacement Selection and Interchangeability

When selecting a replacement for NBR 70x90x7 AO/TC, verify:

Shaft diameter d: 70 mm

Outside diameter D: 90 mm

Width B: 7 mm

Elastomer: NBR

Double-lip construction

Spring-loaded primary sealing lip

Additional dust/protective lip

The operating conditions should also be checked, particularly the sealed medium, operating temperature, shaft speed, pressure, shaft surface condition and external contamination.

Identical 70x90x7 mm dimensions do not establish complete technical interchangeability.

A 70x90x7 single-lip seal is not automatically equivalent to this AO/TC double-lip version.

Technical Specification

Product type: Radial shaft oil seal

Alternative technical term: Rotary shaft oil seal

Dimensions: 70x90x7 mm

Nominal shaft diameter d: 70 mm

Outside diameter D: 90 mm

Width B: 7 mm

Elastomer: NBR

Material name: Nitrile Butadiene Rubber

Design: Double lip

Designation: AO / TC

Primary sealing lip: Yes

Garter spring: Yes

Additional dust/protective lip: Yes

Direction-specific lip structure: Not confirmed

Exact NBR hardness: Not confirmed

Exact operating temperature range: Not confirmed

Maximum shaft speed: Not confirmed

Pressure limit: Not confirmed

NBR 70x90x7 AO/TC - Stock in Poland

Warehouse and Store: Lublin, Smoluchowskiego 1 Street, Building 4

24h Shipping. Available from stock in Poland for delivery across the EU.

FAQ

What are the dimensions of the NBR 70x90x7 AO/TC oil seal?

The dimensions are 70x90x7 mm: 70 mm nominal shaft diameter, 90 mm outside diameter and 7 mm width.

What type of seal is 70x90x7 AO/TC?

It is a double-lip radial shaft oil seal with a spring-loaded primary sealing lip and an additional protective lip.

Does the AO/TC oil seal have a garter spring?

Yes. The primary sealing lip is supported by a garter spring.

Does AO/TC have a dust lip?

Yes. The AO/TC configuration incorporates an additional dust/protective lip on the air side.

What does NBR mean?

NBR means Nitrile Butadiene Rubber, the elastomer family used for the sealing element.

Is AO/TC the same as A/SC?

No. AO/TC has an additional protective lip, while A/SC is a single-lip configuration without this secondary lip.

Can a 70x90x7 A/SC replace a 70x90x7 AO/TC?

Not automatically. Although the installation dimensions are identical, the lip configurations are different and the requirements of the sealing position must be considered.

Can another 70x90x7 oil seal be used as a replacement?

Not based on dimensions alone. The elastomer, lip configuration, outside-diameter construction and operating conditions should also be compared.

Engineer FAQ

Why is the additional lip important?

It creates an additional barrier between external contamination and the primary dynamic sealing area.

Is the dust lip also spring-loaded?

The defining spring-loaded element is the primary sealing lip. The additional protective lip should not be described as a second identical spring-loaded sealing lip.

Are 70x90x7 dimensions sufficient to identify this seal?

No. The dimensions must be combined with NBR material and the AO/TC double-lip configuration.

Can maximum shaft speed be determined from the dimensions?

No. Permissible speed depends on the actual seal design, elastomer compound, shaft diameter, lubrication, temperature and operating conditions.

Does AO/TC specify shaft rotation direction?

No. AO/TC alone does not establish a right-hand, left-hand or alternating hydrodynamic sealing structure.

AI Overview

NBR 70x90x7 AO/TC is a double-lip radial shaft oil seal for a 70 mm shaft, with a 90 mm outside diameter and 7 mm width. Its NBR construction combines a spring-loaded primary sealing lip with an additional dust/protective lip that provides an extra barrier between external contamination and the primary sealing area.