Caster

A caster (also known as castor according to some dictionaries) is a wheeled device typically mounted to a larger object that enables relatively easy rolling movement of the object. Casters are essentially housings, that include a wheel and a mounting to install the caster to objects (equipment, apparatus and more). Casters are found virtually everywhere, from office desk chairs to shipyards, and from hospital beds to automotive factories. They range in size from the very small furniture casters to massive industrial casters, and individual load capacities span 100 pounds (45 kg) or less to 100,000 pounds (45 t). Wheel materials include cast iron, plastic, rubber, polyurethane, polyolefin, nylon, thermoplastic rubber, forged steel, stainless steel, aluminum, and more. A caster (also known as castor according to some dictionaries) is a wheeled device typically mounted to a larger object that enables relatively easy rolling movement of the object. Casters are essentially housings, that include a wheel and a mounting to install the caster to objects (equipment, apparatus and more). Casters are found virtually everywhere, from office desk chairs to shipyards, and from hospital beds to automotive factories. They range in size from the very small furniture casters to massive industrial casters, and individual load capacities span 100 pounds (45 kg) or less to 100,000 pounds (45 t). Wheel materials include cast iron, plastic, rubber, polyurethane, polyolefin, nylon, thermoplastic rubber, forged steel, stainless steel, aluminum, and more. Casters come in two main categories: a swivel caster pivots around a kingpin to allow it to rotate and roll. The rigid (also called 'fixed') caster has its wheel mounted in a fixed frame (also call 'housing,' 'rig,' 'fork,' or 'yoke') and it only rolls forward and backward. This type of caster allows for movement in all directions. They can have one or two sets of raceways that allow the caster to swivel 360-degrees under a load. Because of displacement of wheel axis from steering axis, in spite of their zero caster angle, the point at which the wheel touches the floor trails behind the steering axis, keeping the wheel oriented in the direction of travel. The different types of swivel casters include: