NTN 4T-25878/25820

Single-Row Tapered Roller Bearing

Brand: NTN
Country of Origin: Japan
Item Number: 4T-25878/25820 NTN

Also Known As:

• 25878/25820
• 25878/820
• 25878-20024 / 25820-20024
• 25878-99401

EAN: 4547359524291
Category: Tapered Roller Bearing – Single Row
Weight: 0.464 kg

1. Dimensions

Metric

• Inner Diameter (d): 34.92 mm
• Outer Diameter (D): 73.02 mm
• Width (B): 23.81 mm

Inch

• Inner Diameter: 1.3750 in
• Outer Diameter: 2.8750 in
• Width: 0.9375 in

2. Product Properties

• Bearing Type: Single-row tapered roller bearing
• Precision: Standard precision
• Design: Cup & cone set
• Cone unit: Inner ring + cage + tapered rollers
• Cup: Outer ring
• Load Capability:
• High radial load capacity
• High axial load capacity in one direction
• Construction: Open (no seals – requires external lubrication)

3. Product Description

The NTN 4T-25878/25820 is a high-quality single-row tapered roller bearing designed to carry combined loads, meaning both radial and axial forces. The bearing uses tapered rollers running between conical raceways on the inner and outer rings.

This geometry allows:

• Excellent distribution of loads
• High rigidity under heavy service conditions
• Strong axial load support in one direction (the larger the contact angle, the greater the axial capacity)

The bearing is supplied as a separable cup and cone assembly:

• The cone unit (inner ring, rollers, and cage) and the cup (outer ring) can be mounted separately, which simplifies handling, mounting, and inspection.

Because of the internal construction, single-row tapered roller bearings are normally used in pairs and arranged:

• Back-to-back (O arrangement)
• Face-to-face (X arrangement)
• Tandem, when higher axial load in one direction is required

This allows them to support axial loads in both directions when used together.

4. Typical Applications

• Automotive wheel hubs and axle ends
• Differentials and transmissions
• Gearboxes and industrial gear drives
• Agricultural and construction machinery
• General power transmission where combined loads are present

5. Key Advantages

• Premium Japanese NTN quality
• High radial and axial load capacity in compact size
• Separable cup and cone for easy mounting, dismounting, and inspection
• Standardized dimensions – interchangeable with other 25878/25820 bearing sets
• Suitable for demanding industrial and automotive environments

   PACKAGE INCLUDES: ONE (1) NTN Bearing 25878/25820