KINEX 31308 40x90x25,25 mm - Single Row Tapered Roller Bearing

KINEX 31308 - Product Characteristics

The KINEX 31308 belongs to the family of single row tapered roller bearings used in mechanical assemblies subjected to combined radial and axial loading.

Its tapered rolling elements operate between conical raceways on the inner and outer rings. This geometry enables the bearing to accommodate radial forces together with axial forces acting in one direction.

A single row tapered roller bearing supports externally applied axial loads in one direction. Where axial shaft location is required in both directions, an appropriately designed bearing arrangement is necessary, commonly involving two opposed tapered roller bearings.

The separable construction allows the outer ring to be installed independently from the inner ring assembly.

Correct bearing adjustment, mounting fits and lubrication are essential for reliable operation.

Technical Specifications - KINEX 31308

The manufacturer catalogue confirms the following additional dimensions for the related KINEX 31308A variant:

These additional ring dimensions should not automatically be assigned to the exact 31308 designation without confirming equivalence.

What Does KINEX 31308 Mean?

The designation identifies the manufacturer, bearing series and nominal bore size.

KINEX - Manufacturer

KINEX is a bearing manufacturer associated with the production of rolling bearings for industrial and mechanical applications.

313 - Bearing Series

313 identifies a dimensional and construction series of tapered roller bearings.

Bearings in this series use tapered rollers and raceways to accommodate combined radial and axial loading.

08 - Bore Size Code

The final digits 08 indicate a nominal bore diameter of 40 mm under the standard bearing bore code system.

40x90x25,25 mm - Bearing Dimensions

The nominal dimensions represent:

• Bore diameter (d): 40 mm.

• Outside diameter (D): 90 mm.

• Overall bearing width (T): 25,25 mm.

For tapered roller bearings, the overall assembled width T must be distinguished from the individual widths of the inner and outer rings.

Construction and Operating Principle

The KINEX 31308 tapered roller bearing consists of an inner ring, outer ring, tapered rollers and a cage.

The tapered rollers operate between conical raceways, allowing the bearing to transmit radial and axial forces simultaneously.

When a radial load acts on a tapered roller bearing, the geometry of the rolling elements also generates an axial force component. This must be considered when designing the bearing arrangement.

A single row tapered roller bearing supports axial loads in one direction. For axial location in both directions, an appropriate opposing bearing arrangement is normally required.

The separable design allows the outer ring to be installed independently from the inner ring and roller assembly.

As an open bearing, it requires an appropriate lubrication system and protection against contamination.

KINEX 31308 Compared with Other Tapered Roller Bearing Variants

Bearings with similar dimensions can belong to different series or incorporate different internal designs.

KINEX 31308 vs 31308A

The official KINEX catalogue lists the 31308A variant with dimensions of 40x90x25,25 mm.

However, the additional A designation may identify a specific construction feature.

The two references should not automatically be treated as identical without manufacturer confirmation.

KINEX 31308A vs 30308A

Both variants can share the same principal dimensions of 40x90x25,25 mm.

However, they belong to different tapered roller bearing series and may have different internal geometry, contact angles and load ratings.

Matching dimensions alone do not establish interchangeability.

KINEX 31308A vs 32308A

The 32308A belongs to a different dimensional series and has a greater overall width of 35,25 mm.

It should not be considered a direct replacement for a bearing requiring an overall width of 25,25 mm.

Alternative Designations and Reference Formats

The product may be identified using the following natural designation formats:

• KINEX 31308

• 31308 KINEX

• KINEX 31308 tapered roller bearing

• 31308 KINEX 40x90x25,25 mm

• Single row tapered roller bearing KINEX 31308

The related manufacturer reference KINEX 31308A should be treated as a separate catalogue designation until technical equivalence has been confirmed.

No unverified OEM numbers or direct replacement references are assigned to the exact 31308 product.

Applications of KINEX 31308

Single row tapered roller bearings are used in mechanical assemblies where combined radial and axial loads must be accommodated.

Typical applications for this bearing construction include appropriately designed:

• Mechanical gearboxes and transmissions.

• Rotating shaft support systems.

• Wheel hub assemblies.

• Industrial drive mechanisms.

These are general applications of single row tapered roller bearings, not confirmed equipment applications for the exact KINEX 31308 reference.

Compatibility with a specific machine or mechanical assembly must be verified using the original equipment documentation.

Bearing Selection and Interchangeability

Before purchasing KINEX 31308 or selecting a replacement, verify the following:

1. Complete manufacturer designation: Check whether the original bearing is marked 31308 or 31308A.

2. Bore diameter: 40 mm.

3. Outside diameter: 90 mm.

4. Overall width: 25,25 mm.

5. Individual ring widths: Verify the inner and outer ring dimensions.

6. Internal geometry: Check contact angle, roller configuration and bearing series.

7. Operating requirements: Radial and axial loads, speed and temperature.

8. Mounting conditions: Shaft and housing fits, lubrication and axial adjustment.

Bearings with identical principal dimensions are not necessarily interchangeable.

Differences in internal geometry, contact angle and manufacturing tolerances may affect the operation of the complete bearing arrangement.

Installation and Operating Recommendations

Before installation, clean the shaft, housing bore and all mounting surfaces. Inspect them for damage, wear and dimensional accuracy.

When mounting the bearing, apply installation force only to the ring being fitted with an interference fit.

Never transmit installation force through the tapered rollers and raceways.

Because the bearing is separable, ensure that the outer ring and inner ring assembly are installed correctly and remain free from contamination.

After installation, adjust the axial endplay or preload according to the equipment manufacturer's specifications.

Incorrect adjustment can cause excessive friction, increased operating temperature, vibration and premature bearing wear.

Use the lubricant and lubrication method specified for the mechanical assembly.

Store the bearing in its original protective packaging in a clean, dry environment until installation.

Frequently Asked Questions - FAQ

What are the dimensions of KINEX 31308?

The specified nominal dimensions are 40x90x25,25 mm. These dimensions are also listed in the official KINEX catalogue for the related 31308A variant.

What does 31308 mean in the bearing designation?

313 identifies the tapered roller bearing series, while the final bore code 08 corresponds to a nominal bore diameter of 40 mm.

Are KINEX 31308 and 31308A identical?

Exact equivalence has not been confirmed. The official KINEX catalogue lists 31308A, and the additional A designation should be verified before selecting a replacement.

Can KINEX 31308 accommodate axial loads?

Yes. A single row tapered roller bearing accommodates radial loads and axial loads acting in one direction.

Can KINEX 30308A replace KINEX 31308A?

Not automatically. Although the principal dimensions may match, the bearings belong to different series and can have different internal geometry and operating characteristics.

Does KINEX 31308 require axial adjustment?

Yes. The bearing arrangement requires appropriate axial endplay or preload according to the mechanical assembly's design and operating requirements.

Is KINEX 31308 a sealed bearing?

The described bearing is an open tapered roller bearing. Lubrication and protection against contamination must be provided by the surrounding mechanical assembly.

Can a tapered roller bearing from another manufacturer replace KINEX 31308?

A replacement may be possible, but complete compatibility must be verified. Matching bore diameter, outside diameter and overall width alone is insufficient.

KINEX 31308 - Key Technical Information

KINEX 31308 is a single row tapered roller bearing specified with dimensions of 40x90x25,25 mm. Its separable construction accommodates radial and one-directional axial loads. The official KINEX catalogue confirms these dimensions for the related 31308A variant. Before selecting a replacement, verify the complete designation, internal geometry and mounting requirements.

KINEX Bearings at simmering.pl

KINEX tapered roller bearings are offered through simmering.pl, a specialist supplier of rolling bearings, industrial seals and technical components.

We serve industrial customers, maintenance departments, workshops and technical purchasing teams.

Our warehouse and order processing facilities are located in Lublin, Poland. We provide shipping throughout Europe and worldwide.

Technical assistance is available for bearing identification using manufacturer references, dimensions and application requirements.