Swivel Casters

Swivel casters are designed to rotate 360 degrees, allowing the application they are mounted on to change direction and be steerable. Common examples of swivel casters are chair casters and shopping cart casters. Swivel casters are used in all manners of work from light to extremely heavy duty. There are differences, however, in how they work.

Light duty swivel casters such as those found on chairs and some furniture merely turn on their stem. In these applications this performs fine, as the friction between the caster and the pin never becomes so great that it cannot spin freely. For anything other than the lightest duty casters, other systems are used.

Top Plate Swivel Caster

A Kingpinned Swivel Caster Fork. Note the kingpin bolt in the middle of the top plate, and also the ball bearings below the top plate.

 

A common swivel system is the ball bearing raceway. In this system the caster fork and connection type (whether it be top plate, stem, or anything else) is separated by a ball bearing joint. They are typically held together by a kingpin running from the fork of the caster up through the center of the ball bearing raceway and connected to the connection type. These kingpinned casters are used in all grades of casters from light to heavy duty.

The system used for heavy and extra heavy duty casters is known as Kingpinless, and as the name implies, does not have a kingpin. The connection type and fork on these casters are forged together with ball bearings between them. This provides the smoothest turning and longest lasting swivel type. Kingpinless casters are extremely precise in their machining and construction. The design also allows for better handling of high shock environments and extra heavy duty work where a kingpin could break or fail.