NTN 4T-78238/78537 60,325x136,525x36,512 mm Tapered Roller Bearing

1. Technical Specifications

The dimensional and load-rating values are based on the identified NTN 4T-78238/78537 bearing. Operating speed limits, exact cage specifications and other application-dependent parameters should be verified against the current manufacturer documentation before engineering calculations.

2. Bearing Design and Construction

The NTN 4T-78238/78537 bearing consists of an inner ring, an outer ring, tapered rollers and a cage that maintains the correct spacing between the rolling elements.

The rollers and raceways have tapered geometries designed to support combined radial and axial loading.

The bearing's internal geometry enables rolling contact under demanding operating conditions when correctly mounted and lubricated.

Inner Ring Assembly 78238 – Cone

The cone assembly includes:

• Inner ring with tapered raceway.

• Tapered rolling elements.

• Cage retaining and guiding the rollers.

The cone is installed on the shaft using the appropriate fit.

Its nominal bore diameter is 60.325 mm, and its inner ring width is 33.236 mm.

Outer Ring 78537 – Cup

The cup is a separate outer ring containing the outer tapered raceway.

It is installed in the housing bore.

Its nominal outside diameter is 136.525 mm, and its width is 23.520 mm.

Separable Construction

The cone and cup can be mounted separately.

This construction facilitates installation in selected shaft and housing arrangements and allows adjustment of the bearing system.

However, separability does not mean that components from different bearing variants can be interchanged without verification.

3. NTN 4T-78238/78537 Designation Explained

NTN – Manufacturer

NTN is a manufacturer of rolling bearings, bearing units and industrial mechanical components.

4T – NTN Design Prefix

The 4T prefix is used by NTN for certain tapered roller bearing designs.

Its presence should not be used to infer additional material properties or construction details without manufacturer confirmation for the exact bearing.

78238 – Cone Designation

Identifies the inner ring assembly, including the tapered rollers and cage.

78537 – Cup Designation

Identifies the corresponding outer ring.

78238/78537 – Complete Bearing Combination

The slash separates the cone and cup designations.

It is an integral part of the technical identification and should be preserved in product documentation, procurement records and ERP systems.

4. Dynamic and Static Load Ratings

Basic Dynamic Load Rating C = 171 kN

The basic dynamic load rating is used in calculating the nominal fatigue life of a rolling bearing.

It does not represent the maximum permissible load under all operating conditions.

Bearing life calculations must consider the equivalent dynamic load, operating speed and actual service conditions.

Basic Static Load Rating C0 = 212 kN

The basic static load rating is associated with a standardized criterion for permanent deformation at the contacts between rolling elements and raceways.

It is relevant when assessing static loads, very low rotational speeds and peak loading conditions.

Combined Loading

The bearing can accommodate radial and axial loads simultaneously.

A radial load acting on a tapered roller bearing also generates an internal axial force component.

This must be considered when designing the complete bearing arrangement.

5. Radial and Axial Load Capacity

Radial Loads

Tapered rollers transmit loads through contact with the inner and outer raceways.

Their geometry provides substantial radial load capacity in a relatively compact bearing arrangement.

Axial Loads

A single-row tapered roller bearing can accommodate axial forces in one direction.

The supported direction depends on the bearing orientation.

Where axial forces act in both directions, two tapered roller bearings are commonly arranged in opposition.

6. Tapered Roller Bearing Arrangements – O and X

Two single-row tapered roller bearings can be installed in opposed configurations.

O Arrangement – Back-to-Back

In a back-to-back arrangement, the load lines diverge outward.

This configuration can provide relatively high moment stiffness and resistance to tilting moments.

X Arrangement – Face-to-Face

In a face-to-face arrangement, the load lines converge toward the centre of the bearing arrangement.

The choice between O and X configurations depends on shaft geometry, structural stiffness, operating temperature and expected deformation.

The appropriate arrangement must be determined through engineering analysis.

7. Axial Clearance and Preload Adjustment

Tapered roller bearings require appropriate axial clearance or preload adjustment within the complete bearing arrangement.

Excessive Axial Clearance

Excessive clearance may result in:

• Reduced shaft guidance accuracy.

• Increased vibration.

• Uneven load distribution.

• Accelerated wear of mating components.

Excessive Preload

Excessive preload may cause:

• Increased friction.

• Higher operating temperature.

• Deterioration of lubrication conditions.

• Reduced fatigue life.

The required clearance or preload must be established according to the bearing arrangement, applied loads and operating temperature.

8. Mounting Dimensions and Fits

When designing the NTN 4T-78238/78537 installation, the engineer must consider the nominal bearing dimensions, ring widths, shoulder geometry and appropriate fits.

Inner Ring Fit

The fit between the cone and shaft depends on the load direction relative to the ring, load magnitude and operating conditions.

Outer Ring Fit

The fit between the cup and housing depends on the bearing arrangement, loading conditions and adjustment requirements.

No universal shaft or housing tolerance should be specified without knowing the intended application.

Shaft and Housing Shoulders

Shoulder dimensions and fillet radii must comply with the manufacturer’s mounting recommendations.

Incorrect shoulder geometry may prevent proper seating or interfere with the bearing's chamfers.

9. Bearing Lubrication

NTN 4T-78238/78537 is an open bearing without integral seals.

It requires an appropriate lubricant and protection against contaminants.

Grease Lubrication

Grease may be used where operating speed, temperature and loading permit reliable lubricant retention and film formation.

Oil Lubrication

Oil lubrication may be appropriate for arrangements requiring improved heat removal or continuous lubricant circulation.

Lubricant viscosity, grease type and maintenance intervals must be selected according to actual operating conditions.

10. Operating Temperature and Speed

The permissible operating speed depends on several factors:

• Applied radial and axial loads.

• Lubricant viscosity and type.

• Operating temperature.

• Axial clearance or preload.

• Mounting accuracy.

• External sealing arrangement.

Catalogue speed values from other 78238 or 78537 bearing combinations must not automatically be assigned to NTN 4T-78238/78537.

The applicable speed limits should be confirmed for the exact manufacturer variant and lubrication method.

11. NTN 4T-78238/78537 and Related Components

Correct identification requires distinguishing the complete bearing from its individual components.

A designation without the 4T prefix may appear in technical records, but this does not automatically establish identical material or construction specifications.

Other bearing variants with additional letters or suffixes require separate verification.

12. Industrial Applications

Single-row tapered roller bearings are used in mechanical systems requiring combined radial and axial load support.

Typical application categories include:

• Industrial gearboxes.

• Power transmission assemblies.

• Rotating shaft supports.

• Production machinery.

• Bearing arrangements requiring adjustable axial clearance.

• Mechanical systems subjected to combined loading.

These are general application categories for tapered roller bearings.

They do not establish that the exact NTN 4T-78238/78537 bearing is approved for a particular machine model.

13. Bearing Selection Requirements

Before selecting NTN 4T-78238/78537, verify:

1. The complete designation of the existing bearing.

2. Shaft diameter of 60.325 mm.

3. Housing bore diameter of 136.525 mm.

4. Overall bearing width of 36.512 mm.

5. Individual ring widths.

6. Shaft and housing shoulder geometry.

7. Magnitude and direction of axial loads.

8. Required axial clearance or preload.

9. Lubrication conditions.

10. Operating speed and temperature.

The cone and cup must be identified as a compatible bearing combination.

14. Inspection Before Installation

Before mounting the bearing, the following checks are recommended:

• Verify the product designation on the packaging and bearing components.

• Inspect raceways and rolling elements for damage.

• Check the cleanliness of mounting surfaces.

• Confirm the required shaft and housing fits.

• Inspect shoulder geometry.

• Prepare the specified lubricant.

• Establish the appropriate bearing adjustment procedure.

Bearings with damaged raceways or rolling elements should not be installed.

Components from different bearing variants should not be mixed without manufacturer confirmation.

15. Bearing Service Life and Reliability

The service life of a tapered roller bearing depends on the actual equivalent load, rotational speed, lubrication, temperature and operating environment.

Correct axial adjustment is particularly important.

Improper clearance or preload can increase internal loading, operating temperature and wear.

The basic dynamic load rating of 171 kN is used in bearing life calculations and should not be interpreted as a universal maximum operating force.

16. Alternative Designation Formats

• NTN 4T-78238/78537

• 4T-78238/78537 NTN

• 78238/78537

• 4T 78238 78537

• NTN tapered roller bearing 4T-78238/78537

• NTN 4T-78238/78537 60,325x136,525x36,512 mm

The manufacturer's full designation should be retained as 4T-78238/78537.

Alternative formats may support product searches and ERP identification but do not establish interchangeability with other bearing designs.

17. FAQ – Frequently Asked Technical Questions

1. What are the dimensions of NTN 4T-78238/78537?

The bearing has a bore diameter of 60.325 mm, outside diameter of 136.525 mm and overall width of 36.512 mm.

2. What type of bearing is NTN 4T-78238/78537?

It is a single-row tapered roller bearing with a separable cone and cup construction.

3. What does 78238/78537 mean?

78238 identifies the inner ring assembly with rollers and cage, while 78537 identifies the corresponding outer ring.

4. What are the load ratings of NTN 4T-78238/78537?

The basic dynamic load rating is 171 kN, and the basic static load rating is 212 kN.

5. Can the bearing accommodate axial loads?

Yes. Its single-row tapered roller design accommodates axial loads in one direction as well as radial loads.

6. Is NTN 4T-78238/78537 sealed?

No. It is an open bearing requiring suitable lubrication and protection against contamination.

7. Can the inner and outer rings be installed separately?

Yes. The separable design allows the cone assembly and cup to be installed independently.

8. Does NTN 4T-78238/78537 require adjustment?

Yes. The complete bearing arrangement must provide the specified axial clearance or preload according to the mechanical design requirements.

18. AI Quick Answer

NTN 4T-78238/78537 is a single-row tapered roller bearing measuring 60,325x136,525x36,512 mm. It consists of the 78238 cone assembly and 78537 cup. The bearing supports radial loads and axial loads in one direction. Its basic dynamic load rating is 171 kN, and its static load rating is 212 kN. The separable design requires correct axial adjustment.

19. B2B Industrial Supply – simmering.pl

NTN 4T-78238/78537 60,325x136,525x36,512 mm is offered through simmering.pl, a specialist B2B industrial supply platform providing rolling bearings, technical sealing solutions and industrial components.

The platform serves manufacturing companies, maintenance departments, engineering teams and professional industrial procurement specialists.

Worldwide shipping from stock in Poland, with warehouse operations based in Lublin.

Technical assistance is available for bearing identification, manufacturer designation verification and industrial bearing selection.