GRN 25x35x7 B1 NBR Single-Lip Rotary Shaft Seal

GRN 25x35x7 B1 NBR Single-Lip Rotary Shaft Seal

GRN 25x35x7 B1 NBR is a single-lip radial rotary shaft seal with dimensions 25x35x7 mm. The B1 design corresponds to DIN 3760 Type B and features an exposed metal outer case, one primary sealing lip made from NBR and a garter spring. The standard B1 design does not have an additional dust lip.

Technical Data

What Does 25x35x7 B1 NBR Mean?

25x35x7 defines the nominal seal dimensions:

• 25 mm shaft diameter

• 35 mm outside diameter

• 7 mm width

B1 identifies a single-lip radial shaft seal with an exposed metal outer case and a spring-loaded primary sealing lip. The standard B1 design has no additional dust lip.

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

B1 Seal Design

The B1 profile is characterized by its metal outer surface.

Its construction includes:

• exposed metal outer case,

• NBR sealing element,

• one primary sealing lip,

• garter spring,

• no additional dust lip.

The garter spring helps maintain contact between the primary sealing lip and the rotating shaft.

The B1 construction corresponds to DIN 3760 Type B.

Metal Outer Case

Unlike rotary shaft seals with a rubber-covered outside diameter, the B1 design has an exposed metal outer surface that fits directly into the housing bore.

For this reason, the condition and accuracy of the housing bore are particularly important.

Check:

• housing bore dimensions,

• surface condition,

• cleanliness,

• correct alignment,

• correct interference fit.

A metal-cased B1 seal and a rubber-covered seal with identical dimensions should not automatically be considered fully interchangeable.

NBR Sealing Material

The sealing element is manufactured from NBR - Nitrile Butadiene Rubber.

NBR is widely used for radial shaft seals operating with many common mineral oils, greases and lubricants.

Compatibility should always be checked against the actual medium and operating conditions. A specific temperature range should not be assumed solely from the general properties of NBR.

B1 vs B1SL

B1 and B1SL are different seal designs.

B1:

• single primary sealing lip,

• garter spring,

• exposed metal outer case,

• no additional dust lip.

B1SL:

• primary sealing lip,

• metal outer case,

• additional dust lip.

If the original application requires an additional protective lip, a standard B1 seal should not automatically be used as a replacement.

Alternative Designations and Search References

This seal may be searched for as:

• 25x35x7 B1 NBR

• B1 25x35x7 NBR

• 25X35X7 B1

• 25x35x7 Type B NBR

• 25x35x7 metal case oil seal

• 25x35x7 single-lip rotary shaft seal

Under DIN 3760 terminology, the B1 construction corresponds to Type B.

Profile codes used by different seal manufacturers are not completely standardized. Always compare the actual construction when selecting an equivalent product.

Typical Applications of B1 Rotary Shaft Seals

B1 radial shaft seals are designed for dynamic sealing of rotating shafts.

This type of construction can be found in:

• gearboxes,

• axles,

• power tools,

• industrial machinery,

• mechanical equipment.

These are typical applications for this type of seal construction and do not confirm that this specific 25x35x7 mm size is used in a particular machine or assembly.

Selection and Interchangeability

Before ordering, verify:

1. Shaft diameter - 25 mm.

2. Housing bore diameter - 35 mm.

3. Seal width - 7 mm.

4. Profile - B1.

5. Material - NBR.

6. Garter spring - yes.

7. Additional dust lip - no.

8. Outer surface - metal.

9. Compatibility with the operating medium and conditions.

Identical 25x35x7 mm dimensions do not automatically mean that two rotary shaft seals are fully interchangeable.

A rubber-covered seal, double-lip seal or seal manufactured from a different elastomer may have the same nominal dimensions but a different construction and operating characteristics.

Installation

Before installation, clean and inspect the shaft and housing bore.

Check for:

• shaft wear grooves,

• scratches,

• corrosion,

• contamination,

• damaged housing surfaces,

• sharp edges,

• excessive shaft runout,

• bearing play.

Install the seal squarely and evenly using a suitable installation tool. Avoid deforming the metal case or damaging the sealing lip.

Because the B1 design has an exposed metal outside diameter, the condition and dimensional accuracy of the housing bore are particularly important.

FAQ

What are the dimensions of the GRN B1 oil seal?

The dimensions are 25x35x7 mm: 25 mm shaft diameter, 35 mm outside diameter and 7 mm width.

What does B1 mean?

B1 identifies a radial shaft seal with an exposed metal outer case, one primary sealing lip and a garter spring.

Does the B1 seal have a dust lip?

No. The standard B1 design does not have an additional dust lip.

Does the 25x35x7 B1 seal have a spring?

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

What does NBR mean?

NBR stands for Nitrile Butadiene Rubber, a sealing material commonly used with many mineral oils and greases.

Are B1 and B1SL the same?

No. B1 has no additional dust lip, while B1SL includes an additional protective lip.

Can any 25x35x7 oil seal replace this B1 seal?

Not automatically. The dimensions, material, outer-case construction and lip configuration must be checked.

Does B1 correspond to DIN 3760 Type B?

Yes. The B1 construction corresponds to DIN 3760 Type B.

GRN 25x35x7 B1 NBR - Key Information

GRN 25x35x7 B1 NBR is a single-lip radial rotary shaft seal for a 25 mm shaft, with a 35 mm outside diameter and 7 mm width. The B1 design corresponds to DIN 3760 Type B and combines an exposed metal outer case, an NBR primary sealing lip and a garter spring, without an additional dust lip.

Available from simmering.pl

GRN 25x35x7 B1 NBR is available from simmering.pl, a specialist supplier of rotary shaft seals, cassette seals, O-rings, V-rings and bearings.

Stock in Poland. Worldwide shipping and technical support for seal identification are available.