Product Introduction

The 32900 series tapered Roller Bearings feature an ultra-thin-walled, compact design with minimal outer diameters and narrow widths. They are indispensable in applications where radial space is extremely limited, such as small gearboxes, precision wheel hubs, and space-constrained transmission mechanisms.

As a single row Tapered Roller Bearing series with a diameter series code of "29" and a contact angle of approximately 12° to 18°, this series offers the most compact radial dimensions among all single-row variants. With outer diameters and widths significantly smaller than those of the 30200 series, they are ideal for precision applications involving limited housing space and moderate loads.

Single row Tapered Roller Bearings are among the most widely used rolling bearings in industry. They consist of an inner ring with a tapered raceway and a large guide flange, an outer ring with a cup-shaped tapered raceway, and a single row of tapered rollers positioned between them. The extended lines of all conical surfaces converge at a single point on the bearing axis, ensuring pure rolling motion for the rollers. As separable bearings, the inner ring assembly and outer ring can be mounted independently. They can simultaneously support radial loads and unidirectional axial loads; typically, they are installed in opposing pairs to provide bidirectional axial location. They are widely used in sectors such as automotive, construction machinery, mining, and speed reducers.

Key Features

Ultra-thin-walled design: For a given inner diameter, the outer diameter is 15–25 mm smaller and the width is 4–8 mm narrower than the 30200 series, minimizing radial space requirements.

Light-load positioning: Short rollers and small contact areas result in limited load-carrying capacity, making them suitable for light to moderate loads.

Relatively high rotational speed: Small, lightweight rollers generate less frictional heat, resulting in a higher limiting speed compared to other tapered roller bearings.

Suitable for precision applications: Compact dimensions accommodate space-sensitive equipment such as machine tools and instruments.

Dimensional Parameter Table

The basic dimensions of WGHB tapered roller bearings are listed in the dimensional data sheet

Single Row Tapered Roller Bearings: Most basic and widely used tapered bearing. Usually fitted as one of an opposing pair. During equipment assembly, can be set to the required clearance (end play) or preload condition to optimize performance. 

Single row (Type 30000): The most common type; primarily accommodates combined loads with a dominant radial component.

Inner diameter size range: 20mm~1270mm

Outer diameter range: 40mm~1465mm

Width size range: 15mm~240mm

Double Row Tapered Roller Bearings: Double row tapered bearing arrangements offer increased load capacity over single types.

Double row (Type 350000): Capable of supporting radial loads as well as bidirectional axial loads; commonly used in applications such as passenger car wheel hubs.

Inner diameter size range: 38mm~1560mm

Outer diameter range: 70mm~1800mm

Width size range: 50mm~460mm

Four Row Tapered Roller Bearings: Combine the inherent high-load, radial/thrust capacity and direct/indirect mounting variables of tapered roller bearings into assemblies of maximum load rating in a minimal space.

Four row (Type 380000): Features higher load-carrying capacity and is primarily used in heavy machinery, such as rolling mills.

Inner diameter size range: 130mm~1600mm

Outer diameter size range: 200mm~2000mm

Width size range: 150mm~1150mm

Unique Value

The core value of the 32900 Series Tapered Roller Bearings is the ability to **"deliver tapered roller bearing performance within minimal space."** Comparing the 32910 (50×72×15) with the 30210 (50×90×21.75): for the same inner diameter, the 32910 has an outer diameter that is 18mm smaller and a width that is 6.75mm smaller, saving approximately 20% in radial space. When equipment design is finalized and the housing bore size cannot be increased, the 329 series serves as the last viable option for fitting in a tapered roller bearing.

Common Suffixes

J: Pressed steel cage

P5 / P4: Precision class (P5 is commonly used for precision machinery)

C3 / C4: Large internal clearance

W33: Outer ring with lubrication groove and oil holes

/K: Tapered bore design

Quick Reference for Common Models

32906  30×47×12  Small gearboxes, power tools

32908  40×62×15  Precision wheel hubs, pump shafts

32910  50×72×15  Machine tool spindles, speed reducers

32912  60×85×17  Textile machinery, packaging machinery

32914  70×100×20  Medium-sized gearboxes, conveyors

32916  80×110×20  Construction machinery auxiliary shafts, agricultural machinery

32920  100×140×25  Large speed reducers, metallurgical equipment

32924  120×165×30  Mining machinery, conveyors

Application Scenarios

Precision Machinery: Machine tool spindles, indexing mechanisms, and woodworking machinery; models 32908 through 32914 are commonly used in applications requiring compact dimensions and a certain level of axial load-bearing capacity.

Small Gearboxes: Micro-reducers, servo motor shaft ends, and robot joints; the ultra-thin wall design of the 32900 series is the only choice where radial space is limited.

Textile and Packaging: Textile machine spindles and packaging machine rollers; suitable for light-load, medium-to-high-speed operations, with compact dimensions that fit the equipment structure. Automotive and agricultural machinery: Suitable for certain compact wheel hubs and small transmission mechanisms; corresponding imperial-sized replacement models are also available.

Large-scale/specialized applications: Large models (size 32940 and above) are used in large-scale speed reducers and metallurgical equipment where radial space is limited.

Selection Recommendations

The 32900 series is suitable for operating conditions involving light loads, space constraints, and medium-to-high speeds. If space permits and loads are heavier, the 30200 or 33000 series is more appropriate; if higher axial load capacity is required, consider the 32000 series.