Caster Tech Glossary of Terms

The following is a list of terms that are used throughout the Caster industry. Take a few minutes to review this important information and as always if you have any questions feel free to reach out and talk to one of our knowledgable customer service and sales associates. We look forward to solving your caster and wheel needs.

Casters

A caster is a wheeled device designed to facilitate movement, commonly used in industrial, commercial, and institutional applications. Casters are composed of two main components: the rig and the wheel.

Caster Types

Swivel Caster – A caster that moves forward and backward and rotates to change direction.

Rigid Caster – A caster that only moves in a straight line, without rotation.

Brake Caster – A caster with an accessory to stop movement. Some brakes lock only the wheel, while total lock brakes secure both the wheel and swivel mechanism.

Swivel Locks – Accessories that prevent swivel rotation, improving control during straight-line movement. Swivel locks may be paired with wheel-contact brakes.

Caster Rigs

The rig is the assembly that connects the caster wheel to the mounting system.

Rig Components

Kingpin – A threaded bolt and nut or a staked component that holds the swivel assembly together.

Kingpinless – A caster design where ball bearings secure the top plate and legs without a traditional kingpin, offering improved durability.

Raceway – The track housing ball bearings that enable smooth swiveling.

Single Race – A single row of ball bearings in the raceway.

Dual Race – Two rows of ball bearings for enhanced swivel performance.

Fork (Horn, Yoke, Frame) – The part of the caster that holds the wheel and attaches to the fastening system.

Stamped Fork – A single-piece metal fork formed in a press, such as those in the Albion 02 Series.

Welded Fork – A fork with welded legs for increased strength.

Fastening – The connection method between the caster and equipment.

• Top Plate – A flat plate for secure attachment to equipment.
• Threaded Stem – A threaded fastening that screws into a receptacle or frame.
• Expanding Adapter – A rubber bushing mechanism that expands within a tube for secure attachment.
• Hollow Kingpin – A fastening with an open hole allowing a bolt to pass through.

Caster Wheels

The wheel is the part of the caster that makes contact with the floor. Wheel selection impacts rollability, noise, shock absorption, and chemical resistance.

Wheel Components

Tread – The outer part that touches the floor.

Core – The inner structure of the wheel, providing strength.

Bore – The hollow center where the axle or bearing is inserted.

Hub – A reinforced section around the bore that may interact with brakes.

Wheel Types

Polyurethane Wheels – Designed for durability, noise reduction, shock absorption, and debris resistance.

Rubber Wheels – Ideal for floor protection and shock absorption, available in non-marking, semi-pneumatic, and full pneumatic options.

Metal Wheels – High-capacity wheels for extreme applications, made of cast iron, ductile iron, or forged steel.

Phenolic Wheels – Made from compressed macerated materials and phenolic resins for an economical yet strong option.

Nylon & Glass-Filled Wheels – High load capacity and wash-down resistant.

Polypropylene Wheels – Lightweight and cost-effective, commonly made from thermoplastic polymers.

Wheel Bearings

Roller Bearing – The industry standard, featuring a steel roller cage.

Industrial Radial Bearing – Shielded ball bearings pressed into the hub.

Torrington-Style Roller Bearing – A metal-caged roller bearing for increased rigidity.

Annular Ball Bearing – A precision-machined bearing offering smooth rolling and quiet operation.

Precision Tapered Roller Bearing – The best choice for heavy or towed loads.

Precision Sealed Ball Bearing – A sealed bearing eliminating the need for lubrication.

Sintered Iron (Oilex) Bearing – Self-lubricating, ideal for applications with difficult access for maintenance.

Delrin Bearing – A self-lubricating engineered plastic bearing, ideal for high-wash environments.

Retaining Washer – Holds bearings in place, with sealed versions available for added protection.

Caster Measurements

Load Rating/Capacity – The maximum weight a caster can support.

Overall Height (Mounting Height, Load Height) – The vertical distance from the floor to the top of the mounting plate or base of the stem.

Swivel Lead – The distance between the kingpin centerline and axle centerline; affects maneuverability and strength.

Swivel Radius – The horizontal distance from the kingpin center to the edge of the wheel tread.

Tread Width – The measurement of the wheel’s width.

Wheel Diameter – The height of the wheel measured from one side of the tread to the other.

Durometer – The hardness scale for wheel materials, impacting durability and performance.