Angular contact ball bearings

Angular contact bearings are designed such that a contact angle between the races and the balls is formed when the bearing is in use. The major design characteristic of this type of bearing is that one, or both of the ring races have one shoulder relieved, or higher than the other. In order for these bearings to function properly, they must be assembled with a thrust load. This loading (or preload) creates a line of contact (or contact angle) between the inner race, the ball and the outer race. The preload can be built into the bearing or created when the bearing is inserted into an assembly. The contact angle varies from 15° to 40° and is measured relative to a line running perpendicular to the bearing axis. Angular contact bearings are unidirectional thrust bearings that can withstand heavy thrust loads and moderate radial loads.

Important dimensions to consider when searching for angular contact bearings include design units bore, outside diameters, and outer ring width.  Design units can be in either inches or metric units.  Some manufacturers may specify parts in both.  The bearing industry uses a standard number system for bearings with metric diameter bores.  For bore sizes 04 and up multiply by 5 to obtain the bore in millimeters. 

Important operating specifications to consider when searching for angular contact bearings include rated speed, static radial load, and dynamic radial load.  The rated speed of a bearing running with grease lubrication is lower than that of a bearing with oil lubrication.  The static radial load is the maximum radial load a bearing can endure without excessive permanent deformation.  The dynamic radial load is the calculated constant radial load, which a group of identical bearings with stationary outer rings can theoretically endure for a rating life of 1 million revolutions of the inner ring.

Manufacturers typically assign an ABEC rating to bearings.  ABEC (Annular Bearing Engineers' Committee) ratings classify different accuracy and tolerance ranges for bearings. The higher the ABEC number the tighter the bearing tolerances.  Please consult the tables in the search form for Angular Contact Bearings for tolerances and other rating equivalents.

Angular contact bearings can have a number of different styles of seals or shielding.  Seals and shields provide protection from contamination and serve as a retainer for lubricant.  Seals provide better protection and lubricant containment than shields, but have lower maximum speed capabilities.  The different types include single/double seal or single/double shield.  Angular contact bearings may be constructed of special materials including stainless steel, plastic, and ceramic hybrid. They may also be plated; common plating materials are cadmium and chrome.

Bearing design for angular contact bearings can be one directional thrust, double directional thrust, double row, double row maximum capacity angular, duplex thrust, and four-pointed contact.  Thin-section bearings have small cross-sections with respect to their diameter.   Bearings with ball screw support are specially designed for use in ball screw or lead screw applications.  Some bearings may also be flanged.  Angular contact bearings may have a variety of lubrication options. They can be re-lubricated, pre-lubricated, or have solid lubrication.

Angular contact ball bearings are suitable for applications which require high accuracy and good high-speed performance. This type of bearing is designed to carry a combined load.

Single-row angular contact ball bearings and matched pair angular contact ball bearings

The standard contact angles are 15°, 30° and 40°. They are identified, respectively, by the supplementary codes "C", "A" (omitted) and "B". Bearings with a smaller contact angle are more suitable for applications involving high-speed rotation. Those with a larger contact angle feature superior axial load resistance. Angular contact ball bearings are often preloaded to enhance their rigidity and rotating performance. For high-precision matched pair angular contact ball bearings of class 5 or higher, which are used in machine tools and other precision equipment, the standard preload is specified in three levels: light (L) , medium (M) , and heavy (H).

When this type of bearing is loaded radially, an axial component of force is produced. In this case, two (facing one another) or more bearings are matched and assembled.

Double-row angular contact ball bearings

This type of bearings consists of two single-row angular contact ball bearings matched back-to-back, with inner and outer rings integrated.

Four point contact ball bearing

These bearings have a contact angle of 35° and an inner ring divided into two annular pieces. They are suitable for applications that involve either axial or combined loading, where the axial load makes up the major part of the load.  Another advantage is that they are able to support axial load and a certain degree of radial load. Each rolling element is in contact with each of the inner and outer rings at a single point. Both contact points lie on the contact angle line. The line runs to either the right or left depending on the direction of the axial load.

It is essential to carefully examine the application conditions, especially load magnitudes, when choosing appropriate four-point contact ball bearings. Therefore, you are invited to consult us if you are considering installing this type of bearing in your product(s).


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