How to Select Casters
Before you purchase any casters, you need to consider many factors. There are so many industries and applications that require specific features on casters, that we like to first evaluate the whole environment and requirements, and then match the perfect caster to each unique situation. If you’d like to take advantage of our 33 years in the caster industry while working with tens of thousands of clients, feel free to contact us at any time. We can work through the caster selection process along your side. Either way, the information below will allow you to make more informed decisions.
INDUSTRIAL OR DIY
Before you get started, know that you will approach industrial casters differently than you will approach CC Vintage casters normally. Our clients choose CC Vintage casters largely based on their aesthetics, but because of our background in industrial casters, you get an incredible-performing caster as well. See how to choose CC Vintage casters here. If you need the highest performance that industrial and heavy-duty casters provide, then then the information below will help get you exactly what you need for your application.
Need help specifically selecting casters for the automotive industry? Visit our page: Selecting Casters for the Automotive Industry.
SELECTING CASTERS: APPLICATION CONSIDERATIONS
Casters are never used in a vacuum. There is an actual facility where these casters will be used. In this facility, these casters will be used in on a specific application. Broadly speaking, most applications will be either hand-held or tugged, which you can read more about below, but the specific conditions of the facility will greatly affect which caster you choose. Consider some of these things.
First, what does the flooring of your facility look like? Is it damaged with large potholes and other impediments? Is the flooring soft or hard? Do you need to preserve your flooring to a high degree?
Varying the tread and material of your caster wheel allows you to navigate these conditions.
Second, what is the weight capacity and speed of the application? The faster you move, the more weight capacity you need in your casters. The caster diameter, width, and material will all affect how much weight your caster can handle at high or low speeds.
To determine the required load capacity for each caster on the cart, the maximum cart load is divided by the number of casters. That result is then multiplied by a safety factor that is dependent upon the applications’ conditions.
C = Required Load Capacity of Caster
L = Maximum Cart Load
W = Cart Weight
n = Number of Casters used
SF = Safety Factor
Manual Transport Indoors = 1.35 (Under 3 MPH)
Manual Transport Outdoors = 1.8 (Under 3 MPH)
Power Driven Transport Indoors = 2 (Under 3 MPH)
Power Driven Transport Outdoors = 3 (Under 3 MPH)
The following is an even simpler form of this equation for a standard four-caster cart with 2 swivel and 2 rigid casters that has even weight distribution on each wheel under indoor manual transport conditions:
C = Required Load Capacity of Caster
L = Maximum Cart Load
W = Cart Weight
For example, consider a 300 lbs. cart with a 1,800 pound load on it. This would be 2,100 lbs. divided by 3. Each caster would have to support/be rated for 700 pounds or more for this load.
Additional factors should be evaluated to specify the exact caster needed for the application, such as: caster configuration, environment temperature, duty cycle, tread materials, and speed (wheels fitted with ball bearings will have a reduced load capacity at speeds over 3 MPH).
As always, our solutions experts are available to discuss your application to ensure that the correct casters are used because there is more to a caster than just the wheel.
Third, what is the general temperature and climate of your facility? Will the casters be used indoors or outdoors? Specific temperatures whether that be in an actual oven or refrigerator can destroy your casters immediately. We make sure all of our client’s casters match the environment and climate of their application.
Fourth, what are the unique conditions and environments in which your casters will be used? Is there debris? Is there moisture or harmful chemicals? Will the sun constantly beat down on your casters? Will static electricity conduct through your casters and damage valuable products?
All these issues and more need to go into the decision-making process.
You mount your casters to your cart in two main ways: plate-mount or stem-mount. Plate-mount casters are much stronger and are the only choice for heavy weight in industrial facilities. As the name suggests, a flat square plate connects your caster to the bottom of the cart. Make sure to get the right size for your specific cart as the plates come in a few different sizes.
Stem-mount casters use a stem that inserts into the bottom of your cart. Most carts that require stem-mount casters come with casters or with a pre-drilled hole for a specific-sized stem. Stems are commonly used in medical, food-processing, and DIY applications.
SELECTING A CASTER WHEEL
Caster wheels are just one part of the caster, but they are obviously a huge part of the caster as a whole. There are four main components to consider when choosing your wheel: wheel size, tread, and material.
An easy factor to start with is the wheel size. Many of our clients have specific requirements for size. This is often because an engineer has designed a cart and has specific CAD designs, etc., that require a casters of an exact height and caster diameter.
If you’re starting from scratch take into consideration cart storage and other restrictions in your facility. Also, the larger the diameter in general, the easier it will roll and the more weight it will hold, particularly if you increase the width, so if ergonomics and weight capacity is important, you may need to increase the diameter and possible the width of your casters.
Next, consider the material you need. There is no one solution for a wheel’s material. Floor type, temperature, application, etc. will all influence the type of wheel you get. For most industrial applications, we find polyurethane and nylon to be the best choice, but we always assess an application before recommending anything.
Also, it is important to consider the quality of the caster because quality will vary tremendously. For example, polyurethanes vary in rebound resilience and durability. In other words, not all wheels are made alike.
Finally, your caster wheel tread needs to match your facility. The two main types of tread are donut and flat/slightly crowned. A donut tread is better for noise, cushion, debris, and is actually at times better for ergonomics when you have the perfect amount of weight for the wheel. Flat or slightly-crowned caster wheels will handle more weight because there is less compression.
Make sure to consider all of these features when you purchase your caster wheels.
SELECTING A CASTER RIG
Caster rigs are the metal piece that holds the wheel. This part of the casters is just as important as the caster wheel and can literally either make or break your caster.
There are two main types of caster rig: the kingpin and the kingpinless. The kingpin in particular has variations that make a huge difference, and all of these will differ in 3 main ways: connection to top-plate, maintenance, and the overall design and durability.
The kingpin is the base rig for casters and is not suitable for towlines. With a kingpin caster rig, a bolt essentially holds everything together. In some applications, this will become lose and cause the caster to fail. This is the starting point for casters.
The kingpinless caster rig connects the top-plate and the fork with ball bearings inside of a hardened raceway. The bearings themselves keep everything together. This is the starting point for towlines.
A variation of the kingpin is a forged kingpin. This variation is a much more durable than a standard kingpin and is perfect for most applications including towlines. A much larger kingpin connects everything together through forging, which means you don’t ever have the wiggle or give that will develop in a standard kingpin. Many forged kingpins are also maintenance-free.
Wheel bearings are somewhat straightforward. You need to get bearings that will support your specific applications. There are quite a few types of wheel bearings, but two or three will normally suffice for most applications.
In most situations, we use precision ball bearings versus caged roller bearings. Precision ball bearings are substantially more robust and will stand up to most applications including heavy weight in towlines.
A Delrin bearing is used when you have chemicals and moisture involved in more extreme environments. You won’t get the same weight capacity as with a precision ball bearing, but you’ll not have the bearing breaking down either.
ADDING CASTER BRAKES
Casters have many different brake options. The three most common styles of brakes are the side-lock, tech-lock, and total-lock brakes. Side-lock brakes simply tighten down on the wheel hub to cause the wheel to stop moving.
Tech-lock brakes have a direct contact with the wheel and keep the wheel from moving with this friction. With both a side-lock and tech-lock, a swivel casters can move around in 360 degrees although the wheel is locked in place.
A total-lock brake locks both the tread and the swivel. That means that a swivel caster will no longer be able to move around. Industries (such as medical, automotive, technology) that demand the utmost stability with carts will use total-lock brakes.
SELECTING CASTERS FOR ERGONOMICS
Many factors contribute to ergonomics, but push/pull normally dominates our conversations with our clients. In most cases, we need to reduce push/pull as much as possible. However, in most cases some other aspect of the application will guide our decision to select the perfect caster. Is there debris, will the carts also be used in towlines, what is the ideal weight capacity, etc.? These questions and many more help us to dial in on the best caster for each of our unique clients.
Whatever direction we go, we always start off with a push/pull measurement of the old wheels to compare to the old wheels. We undertook a study with The Ohio State University Spine Research Institute to account for injury risk in natural settings. We use these guidelines in our measurements.
SELECTING CASTERS FOR TOWLINES
Towlines keep industrial businesses running day in and day out. Casters in towlines must stand up to rigors that are not found in most other applications. Weight and speed put extra strain on casters. For this reason, you must select the correct rig and caster wheel, or your risk damage to equipment and product as well as severe injury to employees.
You can learn more about towlines here with our article and video.
CASTER WHEEL CONFIGURATIONS
Caster configurations have specific strengths for unique applications. Here are five of the most common configurations you have to choose from. Match these configurations with your particular needs.
2 RIGID 2 SWIVEL
– Most common and affordable arrangement
– For straight movement and/or traveling long distances
– Recommended for heavy or medium loads
– Recommended use depends upon the weight capacity of the casters selected
– Most economical positioning of casters
– Limited to lighter loads
– Prime performance occurs when load wheels are 1/8″ taller than the balance wheels
– Not recommended for ramp use
– Two rigid and two swivel
– Diamond placement provides increased maneuverability
– Not recommended for ramp use
– Optimal caster configuration for applications requiring sideways movement
– Most flexible arrangement
2 RIGID 4 SWIVEL
– Ideal caster configuration for heavy loads and lengthy travel
– Two rigid casters help allocate and reduce the load on the swivel casters
When we assess a client’s facility and application, we consider as many factors as possible to supply our clients with the perfect casters. We want you to succeed for many reasons, but among them is that when you succeed, we succeed. Use these suggestions above to select your perfect casters, and at any time, feel free to contact us so we can figure this out together.