Main Load Bearing
The row of steel balls or rollers that swivels the fork base in relation to the mounting plate of a swivel caster, and counteracts direct thrust.
The flat base, usually with four bolt holes, that forms the top of a caster and permits attachment by bolting or welding to a flat surface.
A surface in which bearing balls or rollers rotate.
A swivel or rigid caster assembly less wheel, that may or may not include axle, nut or spanner bushing.
Secondary Load Commercial/Industrial Bearing
The row of steel balls that rides in the raceway between the fork base and secondary bearing retainer of a swivel caster to counteract component thrust. It is this bearing that characterizes the popular “double ball race” caster.
Secondary Load Precision Bearing
A precision self-contained bearing, usually a tapered roller bearing, operating between the fork base and the kingpin of a swivel caster. Constitutes the most efficient means of assisting swivel action by counteracting component thrust.
A non-rotating sleeve of seamless steel tubing that fits over the axle in many casters. Serves the dual purpose of providing a smooth inner raceway for the wheel bearings, and strengthening the caster by permitting the legs to be tightened against it.
Standard/ Solid Bolt Axle
An axle used to attach the wheel to the fork legs of a caster.
Thrust Washer/Retaining Washer/Combination Seal
A steel washer between the hub ends of the wheel and the inside of the caster legs. A steel washer pressed into the hub ends of some roller bearing wheels to hold the bearing in place.
A round structure, solid disk or a rigid circular ring, that is designed to turn around a center, normally an axle passed through the center of the structure. Caster wheels come in a wide variety of materials, sizes and treads. Often Caster wheel type is synonymous with the material makeup or specialized tread pattern exhibited by the wheel.