Casters Types and Terms

Caster Types

  • Caster wheels are positioned between the legs of the caster to enable mobility.
  • Chair casters are wheel assemblies which are attached to the bottoms of chair legs to improve mobility and shock absorption.
  • Dual wheel casters have resilient tread wheels that help to minimize overall height and maximize load capacity. The differential action of dual wheel casters reduces the "scrubbing" effect of soft treads against the floor, thus improving stability and swivel action.
  • Furniture casters are attached to a variety of furniture for industrial, business and personal use. Furniture caster applications include beds, T.V. stands, chairs and portable tables.
  • Furniture glides protect floors from damage caused by movement of furniture.
  • Furniture wheels are added to the bottom of various pieces of furniture to enable mobility.
  • Heavy-duty casters are used in heavy weight applications involving large or heavy loads and significant shock. Heavy duty casters can withstand loads of more than 300 pounds.
  • Institutional casters are used for the transportation of furniture and equipment in the pharmaceutical, scientific and medical industries.
  • Light-duty casters are designed to handle light loads and low levels of shock and are used for small racks and stands. Load capacities for light duty casters usually range from approximately 75 to 190 pounds per caster.
  • Medium duty casters are designed to handle moderate loads and shock. Used for storage racks, trash cans and office furniture, medium duty casters have load capacities that usually range from approximately 200 to 290 pounds per caster.
  • Pneumatic casters contain air that aids in the absorption of vibration and shock and provides the caster with a smooth roll on bumpy and uneven surfaces. Pneumatic casters are useful in the transportation of sensitive items like medical, electronic and computer equipment.
  • Rigid casters do not swivel but provide only forward and backward motion. Rigid casters, often used in conjunction with swivel caster pairs, are useful in applications involving the transportation of items through an aisle or in a straight path, as they facilitate vertical (up/down) movement.
  • Shock absorbing casters aid in protecting delicate cargo from shock, reduce noise levels and wear on floors and extend the life expectancy of casters, wheels and bearing.
  • Specialty casters are custom-made casters that fulfill a particular need, such as shock absorption and inversion.
  • Stainless casters are made of stainless steel. Stainless casters have great corrosion, rust and chemical resistance and are easy to clean.
  • Swivel casters contain an extra bearing that allows the caster to rotate 360º. Swivel casters, commonly found on office chairs, provide convenient vertical, horizontal and diagonal movement.


Caster Terms

Axle - Caster mechanism that, in conjunction with the nut or bolt, connects the caster wheel to the leg.
 
Bore Size - The amount of space required for caster wheel insertion.
 
Caster Wheel - The rolling caster part that provides movement to the equipment to which the caster is attached. Caster wheels are positioned between the legs of the caster and connected by the axle.
 
Dustcap - The enclosure in which the hardcap sits. The dustcap protects the raceway from foreign materials.
 
Frame - Caster part, also referred to as a "fork," "yoke" or "rig," inside of which the caster wheel rests. The frame consists of two legs to which the caster wheel is attached by means of an axle, nut or bolt and a top plate; swivel casters also contain a swivel bearing between the top plate and the caster legs.
 
Hardcap - The upper raceway that bears the thrust.
 
Hub - The caster wheel core.
 
Leg - Caster part that is connected to the top plate. Legs are also attached to the caster wheel by the axle.
 
Kingpin - In a swivel caster, the rivet inserted into a hole in the center of the top plate to connect the top plate to the rest of the swivel assembly.
 
Load Capacity - The recommended load that an individual caster can accept during standard operation conditions.
 
Mounting Height - Distance measured from the bottom of the unit to the rolling surface.
 
Offset - Distance measured from the center of the axle to the center of the attachment method.
 
Shock Load - The largest load a caster can handle under conditions of shock, such as bumps, uneven surfaces and the dropping of items onto the caster.
 
Spanner Bushing - The round, cylindrical stationary sleeve between the bracket legs, within the bearing and over the axle, through which the axle runs.
 
Static Load - The largest load that a caster can accept while stationary and under no exposure to shock.
 
Swivel Lock - Mechanism on a swivel caster that prevents the swivel from rotating but not from moving forward and backward like a rigid caster.
 
Swivel Raceway - Also known as a "swivel bearing," it is the plate of a swivel caster located between the top plate and the legs that facilitates the swivel movement.
 
Thread Guard - Caster accessory that encases the wheel bearing and shields the caster wheel hub and frame from substances and materials, like threads, that might otherwise gather between the two caster mechanisms.
 
Top Plate - Also referred to as the "base plate" or "mounting plate," it a part of the caster that connects the caster to the equipment and is located on top of the legs or, in the case of swivel casters, the swivel bearing. A rigid top plate contains four holes, one in each corner of the plate, while a swivel top plate contains an additional central hole through which the kingpin is inserted.
 
Yoke - A component that supports the upper and lower raceways.