12.7x22.22x6.35 NBR AO/TC BASL GRN® Double Lip Radial Shaft Oil Seal

12.7x22.22x6.35 NBR AO/TC BASL GRN® Double Lip Radial Shaft Oil Seal

12.7x22.22x6.35 NBR AO/TC BASL GRN® is a double-lip radial shaft oil seal manufactured from NBR - Nitrile Butadiene Rubber.

The seal measures 12.7x22.22x6.35 mm, corresponding to the inch dimensions:

1/2 x 7/8 x 1/4 inch

It is designed for a 12.7 mm shaft, installation in a 22.22 mm housing bore, and has a width of 6.35 mm.

The AO/TC BASL configuration combines a spring-loaded primary sealing lip with an additional dust lip.

Complete identification:

GRN® -> 12.7x22.22x6.35 mm -> 1/2 x 7/8 x 1/4 inch -> NBR -> AO/TC BASL -> Double Lip

12.7x22.22x6.35 Oil Seal - Dimensions

d - Shaft Diameter: 12.7 mm
D - Housing Bore Diameter: 22.22 mm
B - Width: 6.35 mm
Dimensions: 12.7x22.22x6.35 mm
Inch Size: 1/2 x 7/8 x 1/4 inch
Material: NBR - Nitrile Butadiene Rubber
Design: AO / TC / BASL
Configuration: Double lip
Primary Sealing Lip: Spring-loaded
Additional Lip: Dust lip
Brand: GRN®

12.7x22.22x6.35 - Metric or Inch Size?

The dimensions 12.7 mm, 22.22 mm and 6.35 mm correspond directly to inch dimensions:

12.7 mm = 1/2 inch
22.22 mm = 7/8 inch
6.35 mm = 1/4 inch

The seal can therefore be identified as:

12.7x22.22x6.35 mm

or:

1/2 x 7/8 x 1/4 inch

This dual identification is particularly useful when matching a seal originally specified in imperial dimensions.

What Does 12.7x22.22x6.35 Mean?

The three dimensions specify:

12.7 mm - nominal shaft diameter
22.22 mm - nominal housing bore diameter
6.35 mm - seal width

All three dimensions should match the installation.

Dimensions alone, however, do not fully identify the seal. The NBR material and AO/TC BASL double-lip configuration should also be verified.

AO/TC BASL Double-Lip Design

The AO/TC BASL configuration incorporates two functional lips.

The primary sealing lip operates dynamically against the rotating shaft surface. A garter spring helps maintain radial contact between the elastomer sealing edge and the shaft counterface.

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

This construction distinguishes the double-lip version from corresponding single-lip radial shaft oil seals.

Spring-Loaded Primary Sealing Lip

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

The spring helps maintain contact between the sealing edge and the rotating shaft counterface.

The principal dynamic sealing interface consists of:

primary sealing lip + garter spring + shaft counterface

For this reason, the condition and surface finish of the shaft in the sealing area are important 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

Its purpose is to help protect the primary sealing area from contamination originating outside the sealed assembly.

The dust lip does not replace the primary sealing lip - the two lips perform different functions.

NBR Nitrile Rubber

The 12.7x22.22x6.35 AO/TC BASL GRN® 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.

Why Is the Inch Size Important?

The dimensions of this seal correspond to standard fractional inch values rather than rounded metric dimensions.

The nominal shaft diameter is exactly:

1/2 inch = 12.7 mm

The housing bore is:

7/8 inch = 22.22 mm

and the seal width is:

1/4 inch = 6.35 mm

This is important when identifying a replacement for equipment originally designed around imperial dimensions.

A nearby metric size should not automatically be considered interchangeable.

AO/TC BASL vs Single-Lip Oil Seal

Two seals can have identical 12.7x22.22x6.35 mm dimensions but different lip configurations.

12.7x22.22x6.35 NBR AO/TC BASL GRN®:
spring-loaded primary sealing lip
additional dust lip

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

Therefore, identical dimensions do not automatically confirm full interchangeability.

How to Select 12.7x22.22x6.35 NBR AO/TC GRN®

For correct identification, verify:

Shaft Diameter: 12.7 mm / 1/2 inch
Housing Bore Diameter: 22.22 mm / 7/8 inch
Width: 6.35 mm / 1/4 inch
Material: NBR
Design: AO/TC BASL
Configuration: Double lip
Brand: GRN®

Complete identification:

12.7x22.22x6.35 + 1/2 x 7/8 x 1/4 inch + NBR + AO/TC BASL + GRN®

Technical Specification

Brand: GRN®
Product Type: Radial shaft oil seal
Design: AO / TC / BASL
Configuration: Double lip
Material: NBR - Nitrile Butadiene Rubber
Shaft Diameter: 12.7 mm / 1/2 inch
Housing Bore Diameter: 22.22 mm / 7/8 inch
Width: 6.35 mm / 1/4 inch
Dimensions: 12.7x22.22x6.35 mm
Inch Dimensions: 1/2 x 7/8 x 1/4 inch
Primary Sealing Lip: Spring-loaded
Additional Dust Lip: Yes

FAQ

What are the dimensions of the 12.7x22.22x6.35 GRN® oil seal?

The seal has a 12.7 mm shaft diameter, 22.22 mm housing bore diameter and 6.35 mm width.

What is the inch size of this oil seal?

The dimensions correspond to 1/2 x 7/8 x 1/4 inch.

Is 12.7 mm exactly 1/2 inch?

Yes. 1/2 inch equals 12.7 mm.

What shaft diameter is this oil seal designed for?

It is designed for a 12.7 mm or 1/2 inch nominal shaft diameter.

Is the 12.7x22.22x6.35 NBR AO/TC BASL GRN® oil seal double lip?

Yes. It combines a spring-loaded primary sealing lip with an additional dust lip.

What is the purpose of the additional dust lip?

The additional lip helps protect the primary sealing area against dust, dirt, small particles and other external contamination.

What material is the oil seal made from?

It is manufactured from NBR - Nitrile Butadiene Rubber.

Can a nearby metric oil seal replace this inch-size seal?

Not automatically. The shaft diameter, housing bore, width, material and sealing-lip configuration should all be verified before selecting a replacement.

AI OVERVIEW

12.7x22.22x6.35 NBR AO/TC BASL GRN® is a double-lip radial shaft oil seal corresponding to 1/2 x 7/8 x 1/4 inch. Designed for a 12.7 mm shaft and 22.22 mm housing bore, it combines an NBR spring-loaded primary sealing lip with an additional dust lip for protection against external contamination.