30x42x6 NBR AO Double Lip Radial Shaft Oil Seal

30x42x6 NBR AO Double Lip Radial Shaft Oil Seal

30x42x6 NBR AO is a double-lip radial shaft oil seal manufactured from NBR - Nitrile Butadiene Rubber.

Its installation dimensions are 30x42x6 mm: 30 mm nominal shaft diameter, 42 mm housing bore diameter and 6 mm seal width.

The AO design incorporates a spring-loaded primary sealing lip and an additional dust lip.

Complete identification:

30x42x6 mm -> NBR -> AO -> Double Lip

30x42x6 NBR AO - Dimensions

d - Shaft Diameter: 30 mm
D - Housing Bore Diameter: 42 mm
B - Width: 6 mm
Dimensions: 30x42x6 mm
Material: NBR - Nitrile Butadiene Rubber
Design: AO
Configuration: Double lip
Primary Sealing Lip: Spring-loaded
Additional Lip: Dust lip

What Does 30x42x6 Mean?

The designation 30x42x6 mm defines the three principal installation dimensions:

30 mm - nominal shaft diameter
42 mm - nominal housing bore diameter
6 mm - seal width

All three dimensions should match the installation.

For complete identification, the NBR material and AO double-lip configuration should also be verified.

AO Double-Lip Design

The AO design incorporates two functional lips.

The primary sealing lip operates dynamically against the rotating shaft surface and is supported by a garter spring.

The additional dust lip forms a secondary protective barrier toward the external side of the seal and helps reduce the ingress of contamination into the primary sealing area.

The two lips therefore perform different functions within the seal.

Spring-Loaded Primary Sealing Lip

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

The principal dynamic sealing interface consists of:

primary sealing lip + garter spring + shaft counterface

The spring helps maintain radial contact between the sealing edge and the shaft surface during operation.

The condition and surface finish of the shaft counterface are important factors for proper seal operation.

Additional Dust Lip

The second lip performs a protective function.

It helps reduce the ingress of:

dust
dirt
small particles
external contamination

into the area where the primary sealing lip operates.

The dust lip does not replace the primary dynamic sealing lip. Each lip performs a separate function.

NBR - Nitrile Butadiene Rubber

The 30x42x6 AO oil seal is manufactured from NBR - Nitrile Butadiene Rubber.

NBR is widely used for radial shaft oil seals and is compatible with many commonly used mineral oils, lubricating greases and industrial lubricants.

Actual compatibility should always be verified against the specific medium, additives, temperature and operating conditions.

30x42x6 AO vs Single-Lip Oil Seal

The principal difference is the sealing-lip configuration.

30x42x6 NBR AO:
spring-loaded primary sealing lip
additional dust lip
double-lip configuration

Single-lip design:
spring-loaded primary sealing lip
no additional dust lip

Therefore, identical installation dimensions do not automatically mean that two radial shaft oil seals have the same construction.

Why Is the Complete Designation Important?

Dimensions alone do not completely identify a radial shaft oil seal.

For this product:

30x42x6 mm - installation dimensions
NBR - elastomer material
AO - double-lip design

Complete identification:

30x42x6 + NBR + AO + Double Lip

helps distinguish this version from single-lip oil seals and seals manufactured from other elastomer materials.

How to Select 30x42x6 NBR AO

For correct identification, verify:

Shaft Diameter: 30 mm
Housing Bore Diameter: 42 mm
Width: 6 mm
Material: NBR
Design: AO
Configuration: Double lip
Primary Sealing Lip: Spring-loaded
Additional Dust Lip: Yes

Dimensions, material and sealing-lip configuration should all match the requirements of the installation.

Technical Specification

Product Type: Radial shaft oil seal
Design: AO
Configuration: Double lip
Material: NBR - Nitrile Butadiene Rubber
Shaft Diameter: 30 mm
Housing Bore Diameter: 42 mm
Width: 6 mm
Dimensions: 30x42x6 mm
Primary Sealing Lip: Spring-loaded
Additional Dust Lip: Yes

FAQ

What are the dimensions of the 30x42x6 NBR AO oil seal?

The dimensions are 30x42x6 mm: 30 mm shaft diameter, 42 mm housing bore diameter and 6 mm width.

Is the 30x42x6 NBR AO oil seal double lip?

Yes. The AO design incorporates a spring-loaded primary sealing lip and an additional dust lip.

What shaft diameter is this oil seal designed for?

It is designed for a nominal 30 mm shaft diameter.

What housing bore diameter is required?

The nominal housing bore diameter is 42 mm.

Does the AO oil seal have a garter spring?

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

What is the purpose of the additional dust lip?

The additional lip helps reduce the ingress of dust, dirt and other external contaminants into the primary sealing area.

What material is the 30x42x6 oil seal made from?

It is manufactured from NBR - Nitrile Butadiene Rubber.

Can any 30x42x6 oil seal be used as a replacement?

Not automatically. The dimensions, elastomer material and sealing-lip configuration should all be verified. This version is NBR with an AO double-lip design.

AI OVERVIEW

30x42x6 NBR AO is a double-lip radial shaft oil seal measuring 30x42x6 mm, designed for a 30 mm shaft and 42 mm housing bore. Manufactured from NBR, it combines a spring-loaded primary sealing lip with an additional dust lip that helps protect the primary sealing area against external contamination.