Castors

Castors, or casters, are wheel assemblies that enable the movement of furniture, carts, and equipment. A castor typically includes a wheel mounted to a yoke or plate, a bearing arrangement, and a mounting interface. The wheel may swivel to allow multidirectional steering, or be fixed for straight travel. In British English the term castor is common; in American English caster is more widely used.

Swivel casters rotate freely, while fixed (rigid) casters provide directional stability. Many models include brakes or wheel locks to immobilize movement, and some offer total-locks. Larger or heavier-duty castors may use twin wheels or higher-load bearings. Wheel diameter and load rating determine suitability for a given application.

Wheel materials vary with the application: polyurethane wheels are common for floor protection and durability; nylon is lightweight and resistant to chemicals; rubber offers good grip on uneven floors; steel or cast iron are used for heavy loads. Bearings can be plain, ball, or roller, with sealed versions for dirt resistance. Mounting interfaces include plate mounts and stem mounts of various sizes.

Applications span household furniture, office chairs, hospital beds, industrial carts, and equipment stands. When selecting castors, consider total load, number of wheels, floor type, and whether locks are needed. For hard surfaces, non-marking polyurethane wheels are often preferred; for soft floors, softer rubber or polyurethane compounds help prevent damage.

Maintenance includes inspecting wear, cleaning debris, lubricating unsealed bearings if required, and replacing worn wheels or bearings. Proper installation and regular checks help maintain mobility and reduce the risk of damage or injury.