A caster is an undriven wheel that is designed to be attached to the bottom of a larger object to enable that object to be moved. Casters are used in numerous applications, including shopping carts, office chairs, toy wagons, hospital beds, and material handling equipment. High capacity, heavy-duty casters are used in many industrial applications, such as platform trucks, carts, assemblies, and tow lines in plants. Casters may be fixed to roll along a straight line path, or mounted on a pivot or pintle such that the wheel will automatically align itself to the direction of travel. There are two main types of casters:

• Rigid Casters: A basic, rigid caster consists of a wheel mounted to a stationary fork. The orientation of the fork, which is fixed relative to the vehicle, is determined when the caster is mounted to the vehicle. Rigid casters tend to restrict vehicle motion so that the vehicle travels along a straight line.

• Swivel Casters: The swivel caster is designed so that the wheel in the caster can rotate 360 degrees while under load. As the center hub of the wheel revolves around the center of the swivel section, it is said to “cast” in that small circle. Thus, caster! This essential swiveling feature of casters makes it so much easier to move heavy loads and turn tight corners in a warehouse. Swivel casters are available as locking casters, plate casters, stem casters, and kingpinless casters.

Casters are often confused with wheels, but they are more than just a wheel. A caster is an assembly that contains both a wheel and a bracket for it, sometimes called a “fork” . Casters are mounted to an apparatus or piece of equipment to make that apparatus movable.