Casters and Caster Wheels: What’s the Difference?
Most people hear the words casters and caster wheels but aren’t necessarily sure what the difference really is. The Caster comprises the parts that make up the product, including the mounting plate, the rig (axle support brackets extending down from the fork base of a swivel caster or the mounting plate of a rigid caster), the axle and bearings, and the wheel. It is the complete assembly of everything involved in a rigid or swivel caster.
The Caster Wheel is just that, a wheel. It is only one component of the caster. Caster wheels come in a wide variety of materials, sizes, and treads. The combination you choose depends on the weight you need to carry, how fast the cart is traveling, the type of floor material it is going over, whether it’s an indoor or outdoor environment, and more.
Types of Casters
A caster can be one of two types, either a rigid caster or a swivel caster.
A rigid caster consists of a wheel mounted to a stationary fork. The orientation of the fork, which is fixed relative to the vehicle, is determined when the caster is mounted to the vehicle. A rigid caster is primarily utilized for straight-line travel, meaning rolling forward or backward. An example of this is the wheels found on a shopping cart. The front wheels swivel, but the back wheels are rigid. This helps restrict vehicle motion so that the cart travels along a straight line.
While this limits maneuverability, rigid casters are stronger than swivel casters and can handle higher weight capacities.
Like the rigid style caster, a swivel caster wheel is mounted to a fork, but an additional swivel joint above the fork allows it to freely rotate about 360°. This enables the wheel to roll in any direction. This also makes it possible to easily move the vehicle without changing its orientation.
One evolution of the swivel caster is the swivel-on-swivel design. This places a swivel section on top of a swivel section to achieve a longer swivel lead than conventional casters. The big advantage? The reduced force required to rotate and get the caster rolling. Also, the 2nd swivel section transfers energy to the 1st swivel section. This aids with the rotation and reduces the amount of shifting that occurs. This is extremely beneficial when maneuvering the cart in tight areas.
As noted above, casters come in many different sizes and weight capacities, depending on the application. Caster Concepts, for example, is a heavy-duty caster manufacturer. Stem casters and casters for furniture are considered light duty casters and are not manufactured by Caster Concepts.
Heavy Duty Casters generally come with a much larger wheel diameter and tread width along with a wheel (either steel wheels or polyurethane on cast iron) that can withstand a heavier load capacity.
With increases in weight capacity comes the problem of increased push and pull force. This is the amount of force you need to get the wheels moving. Increasing the wheel diameter requires less effort to start rolling and to keep the wheels rolling. While increasing wheel diameter is advantageous, increasing wheel width is not. Wider wheels increase surface pressure, making them more resistant when you are trying to switch directions.
Tread material is another important consideration, and there are a lot of materials to consider. What’s the best choice: rubber or steel? Wrought iron or polyurethane? They all have trade-offs, and knowing the pros and cons of each is critical in determining an acceptable balance between material load capacity and floor protection. https://www.casterconcepts.com/whats-the-difference-in-industrial-caster-wheels/
In general, the heavier the desired caster load capacity, the harder the wheel material will be. But harder wheels like steel have a higher potential to damage your floors. Wheels and casters with softer treads like polyurethane are more resilient and offer the most protection to your floors. These types of casters and wheels can also reduce the accumulation of small obstructions like metal shavings.
If you have additional questions about the types of casters for your application, we would be glad to help. As a leader in industrial caster and wheel solutions for virtually every industry, Caster Concepts has a long history of quality products, outstanding service, and a never-ending desire for exceptional results. Give us a call at 888.799.7166.