Caster & Wheel Terminology

Brake the presence of a stopping mechanism

Brake Type the specific type of brake on a caster; either directional, double-sided, face, face contact, pedal, poly cam, side, side top, single side, tech, top, total or tread lock

Dynamic Capacity the total load that ONE caster is capable of moving on a continuous basis

Face the shape of the wheel’s face

Greaseable Axle an axle with a hole in it; used to insert grease and lubricate the bearing

Inside Bolt Spacing the distance between the centers of adjacent boltholes

Kingpinless a rig constructed without a bolt (i.e. kingpin) attaching the top plate to the rig

Leveling Height the distance available for a leveling caster to change the load’s height

Mounting Type one of three styles of attachment that a caster may have; either top plate, stem or less mounting; both stems and top plates come in various sizes and shapes

Non-marking whether or not the caster wheel tread will leave marks on flooring

Overall Height the vertical distance between the bottom of the wheel and the lowest point where the load is mounted to the caster

Outside Bolt Spacing the distance between the centers of opposite boltholes

Rig the caster housing without a caster

Rig Finish / Coating the color of the rig

Rig Material the material of a caster housing without a wheel

Rig Type the type of rig on a caster determines which determines maneuverability; rigid rigs only allow horizontal movement, swivel rigs allow movement in any direction

Stainless Steel made of stainless steel; resistant to tarnishing and rust

Static Load Capacity the total load that ONE caster is capable of supporting, WITHOUT MOVING, on a continuous basis

Stem Size the dimensions (diameter by length) of the stem on a caster that uses stem mounting

Stem Type the specific type of stem on a caster that uses stem mounting; possible options are expanding, grip neck, grip ring, knurled, modular, octagon, pipe thread, round, side fitting, square or threaded

Swivel Lead the horizontal distance between the center of the swivel section and center of the wheel

Swivel Lock a feature that converts a swivel caster into a rigid-like caster that allows only straight-line movement; available as welded, bolt-on or kingpinless

Swivel Radius the radius of possible maneuverability on a caster that uses a swivel rig; measured by the horizontal distance between the center of the swivel section and the center of the wheel

Swivel Seal upper and lower raceway seals on the rig that prevent debris from disrupting the caster’s ability to swivel

Temperature Maximum the highest temperature at which the caster can safely operate

Temperature Minimum the lowest temperature at which the caster can safely operate

Thread Count the number of threads on a threaded stem

Thread Guard a piece of material that protects the wheel bearing by preventing thread, dirt or other debris from disrupting the wheel’s ability to roll smoothly

Thread Guard Material the material of the thread guard

Thread Pitch the distance between threads on a threaded stem measured in millimeters

Top Plate Length the length of the top plate

Top Plate Pattern the pattern of holes on the plate of a caster that uses top plate mounting

Top Plate Size the dimensions (width by length) of the plate on a caster that uses top plate mounting

Top Plate Thickness the thickness of the top plate

Top Plate Width the width of the top plate

Tread the part of the wheel that rolls along the ground

Tread Category the wheel’s tread material; either rubber, polyurethane, plastic/nylon or metal

Wheel Bearing the type of bearing found between the wheel and axle; impacts the rollability of the wheel

Wheel Color the color of the tread of a wheel

Wheel Count the number of wheels on the caster

Wheel Durometer how hard the wheel is; the position of the wheel material on the Shore hardness scale

Wheel Hub Color the color of the hub of a wheel; only applicable on wheels with different tread and core materials

Wheel Material the material(s) of the caster wheel; see our Wheel Descriptions page for more information

Wheel Size the dimensions (diameter by width) of a caster wheel

Zerk a grease fitting used to lubricate the wheel bearing