Casters are complete wheel and horn assemblies that attach to the bottom of equipment to allow movement and carry loads. There are two basic types of industrial casters: rigid and swivel. Both rigid and swivel industrial casters are made out of materials such as aluminum, brass, chrome, copper, iron, steel, plastic, and rubber. In some cases, the wheel or roller is made of one type of material while the plate, horn, and mounting flange are made of another. Typically, industrial casters are used on trucks and trailers, dollies, and drum-handling equipment.

Types

• Rigid casters permit only straight-line movement.
• Ball wheels are shaped like a ball and are usually found on furniture.
• Stem casters use a stem to mount the wheel.
• Swivel casters allow movement in any direction. Some varieties of swivel casters also include a lock that, when engaged, transforms the swivel into a rigid-style caster.
• Wheel casters include a wheel in the assembly.

Rigid Caster
Swivel Caster
Ball Caster
Swivel Stem Caster
Twin Wheel Caster

Specifications

Important specifications to consider include:

• Load capacity - the maximum weight the caster can bear.
• Wheel tread width - the distance between the outer edge and the inner edge of the threat of a new tire.
• Wheel diameter - the diameter or size of the wheel.

Type of Wheel

Industrial casters use several types of wheels.

• V-grooved wheels can ride on tracks or floors and provide superior traction.
• Flanged track wheels can also ride on tracks, but cannot travel on floors because the flanges mounted on each side of the wheel limit the bearing surface area.
• Pneumatic wheels are filled with air for better shock absorption and usually consist of a rubber tire on a metal rim. Tube and tube-less versions are available.
• Phenolic wheels are created by applying heat and pressure to layers of paper or glass cloth impregnated with synthetic resin.

Wheel Material

Industrial casters can also use wheels made from solid materials such as plastic, polyurethane, metal, and rubber for added strength.

• Plastic wheels can be mounted on metal or plastic hubs.
• Rubber wheels can be mounted on plastic or metal hubs.
• Metal wheels, which are often made of stainless steel, may include forged components.
• Ball wheels are ball-shaped and usually made of brass.

Features

Industrial casters are available with a variety of features.

• Brake included
• Hooded wheel is a half-round tread shaped like a semi-circle
• Meet Food and Drug Administration (FDA) regulations for use in sanitary applications.
• Spring-loaded casters reduce shock.
• Twin wheel casters include two wheels in one housing.
• Stem mountings can include either threaded stems or square stems. Industrial casters that swivel do not include a kingpin so that the top plate and inner raceway are formed from one piece. This provides a superior raceway for shock conditions.
• Air casters use a cushion of air pressure to raise the load for easier moving.

Air caster demo. Video credit: landmovers / CC BY-SA 4.0

Image credits:

Terra Universal Inc. | Grainger | Magnus Mobility Systems | All-Spec