Product Introduction

The 33000 series tapered Roller Bearings feature a narrow, lightweight, and precision design characterized by a narrow width and moderate outer diameter. With a contact angle of approximately 14° to 18°, they are commonly used in precision, light-load applications such as machine tools, gearboxes, and pump shafts. Like the 32900 series, they belong to the compact bearing category but possess a slightly larger outer diameter.

The 33000 series single row Tapered Roller Bearings carry the diameter series code "30" and feature a contact angle of approximately 14° to 18°, classifying them as having a standard small contact angle. Their specifications place them between the 32900 series (ultra-thin) and the 30200 series (standard): the outer diameter is larger than that of the 32900 series but smaller than that of the 30200 series, while the width is narrower than that of the 30200 series; overall, they are designed for precision, light-load applications.

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 are capable of simultaneously supporting radial loads and unidirectional axial loads; typically, they are installed in opposing pairs to provide bidirectional axial location. They find extensive application in sectors such as automotive manufacturing, construction machinery, mining, and gear reducers.

Key Features

Narrow Profile & Light Load: 2–4 mm narrower than the 30200 series; features shorter rollers and is designed for lighter loads.

Moderate Outer Diameter: Larger than the 32900 series but smaller than the 30200 series; housing bore dimensions fall between the two.

High Precision Compatibility: The light-load design suits precision machine tools and instruments; P5 precision class or higher is common.

Good Speed Performance: Short rollers and low friction ensure stable performance under medium-to-high speed conditions.

Dimensional Parameters

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

Common Models

33006  30×55×20  Small machine tools, pump shafts

33008  40×68×22  Gearboxes, precision machinery

33010  50×80×24  Machine tool spindles, speed reducers

33012  60×95×27  Gearboxes, conveyors

33014  70×110×31  Medium-sized speed reducers, construction machinery

33016  80×125×36  Mining machinery, metallurgical equipment

33020  100×150×39  Large speed reducers, rolling mill auxiliary rolls

Common Suffixes

J: Pressed steel cage

P5 / P4: Precision class (P5 commonly used for machine tools)

C3 / C4: Large internal clearance

W33: Outer ring with lubrication groove and oil holes

/K: Tapered bore design

Application Scenarios

Machine Tool Industry: The 33000 series is a standard choice for spindles and feed shafts in general-purpose machine tools. Its light-load, precision design—combined with P5 accuracy—meets requirements for rigidity and rotational precision; models 33008 through 33014 are the most common.

Gearboxes: Used for intermediate shafts and countershafts in automotive and industrial gearboxes where loads are moderate but axial positioning is required; the narrow profile of the 33000 series accommodates compact gearbox layouts. Pumps and Compressors: Centrifugal pumps and vacuum pumps (shaft ends); suitable for light-load, medium-to-high-speed applications where the 33000 series offers superior speed performance compared to the "wide" series.

Industrial Drives: Small-to-medium gear reducers, conveyor rollers, and textile machinery; ideal for applications with moderate loads and space constraints.

Positioning Relative to the 32900 and 30200 Series

The 33000 series occupies a middle ground between the 32900 and 30200 series. Comparing models 33010 (50×80×24), 32910 (50×72×15), and 30210 (50×90×21.75): the 32900 series is the most compact but has the lowest load capacity; the 33000 series has an outer diameter 8mm larger and a width 9mm greater than the 32900 series, resulting in significantly higher load capacity; the 30200 series has a larger outer diameter but is actually narrower than the 33000 series. The 33000 series is characterized by a "medium outer diameter + wider rollers," aiming for enhanced load capacity within a limited outer diameter.

Selection Recommendations

The 33000 series is suitable for operating conditions involving light-to-moderate loads, precision requirements, medium-to-high speeds, and limited space. Choose the 32900 series if space is extremely limited; choose the 30200 series for heavier loads; consider the 32000 or 33100 series if greater axial load capacity is required.