Shock Loading on Caster Wheels: Factors to Consider
Victoria Forney

Shock Loading on Caster Wheels: Factors to Consider

When loading a cart or dolly with equipment or placing wheels on your toolbox or cabinet, your primary concern is how much surface space is available for transferring products simultaneously and effortlessly. However, the base of the portable item is the real champion, especially when providing optimal mobility with a graceful glide. All you have to do is prevent shock loading on caster wheels to reap the benefits. 

With over 150 years of combined experience, it’s safe to say our specialized team at Caster Central in Pembroke, MA, has an extensive and intricate understanding of caster wheels. Alongside providing over 2,500 caster options, we relay the dos and don’ts behind care requirements and choosing the right ones for your needs. Below, the experts at Caster Central explain input shock and ways to prevent this harmful action. 

What Is Shock Loading?

Shock loading happens when casters receive a jolt of sudden stress or pressure during operation, usually more than the manufacturer originally intended for them to handle. A single shock load increases vibrations and tilting, leading to product and equipment damage and personnel injuries. Multiple shock loads cause the top plate to bend and the wheel to deteriorate prematurely, jeopardizing mobility. 

How Does Shock Loading Occur?

The best way to prevent mechanical shock is by firstly understanding how they occur. Loads that surpass the casters’ maximum load capacity place excessive stress on the wheels, especially if you haven’t outfitted your equipment with the appropriate materials. 

Determine the caster size by adding the equipment weight and the maximum load in pounds and dividing that number by one less than the number of casters you intend to use for the equipment. If under 350 pounds per caster, you have a one-inch caster diameter minimum. If between 350 and 1,250 pounds, a 2-inch caster is ideal, but for heavier payloads, choose nothing less than a three-inch caster. 

Aside from using undersized casters, ensure you don’t do the following:

  • Slam loads onto the surface: Even acceptably-sized loads dropped aggressively over the casters multiply the load’s force in that instant, adding additional pressure to the wheels. It also affects the swivel section and top plate.
  • Drop the cart on the floor: Just as dropping heavy loads on the cart causes the casters to bang against the floor, dropping the cart directly onto the floor, such as when unstacking or stacking equipment at the beginning or end of a shift, leads to the same outcome. 
  • Create harsh movement: Whether you’re having swivel chair races down the hallway, moving caster equipment with a tugger, or regularly using the casters, such as with everyday wheelchair use, these casters see high speeds, sharp turns, and abrasive surfaces. These factors increase strain rates and encourage shock loading. 
  • Encourage side impact: Moving the cart or dolly without precaution and banging it against walls and other equipment causes side impact that forces the wheels to bounce back and the device to ricochet off the obstacle. 

Preventing Shock Loading with Spring-Loaded Casters

Although you should practice caution when dealing with equipment on casters to reduce pressure on the components, some force-causing situations are inevitable. If you work in manufacturing or construction, where floors aren’t always kept smooth or clean of debris and forklifts and other larger machinery run into the casters, spring-loaded casters may be the way to go. 

Shock-absorbing casters use springs to cushion the weight placed on the wheels, which proves helpful when the flooring is uneven, damaged, or dirty. The buoyancy also absorbs the vibrations from any sudden side, top, and bottom impacts during transportation. However, like traditional casters, spring-loaded ones come in numerous styles, so finding the appropriate one for your needs is vital. 

Finding the Right Spring-Loaded Casters

Considering the level of defection provided by your spring-loaded casters is essential for the safety of your equipment, workers, and casters. For instance, if you have spring casters stronger than the load you intend to move, you’ll notice the spring constant is too high, meaning there’s little to no deflection, which is like not having a spring at all. That means there’s no shock absorption during movement. 

On the other hand, if you overload your cart or dolly with heavy payloads, the spring constant will be too low, leaving no travel for the spring to absorb the impacts. This action causes more harm than not having a spring-loaded caster since it prolongs the vibrations, increasing the effects of the collision. 

However, for safety reasons, to ensure you’re not overloading your casters or the springs, we design the casters and surrounding parts (except the spring) to take on a given load capacity. When you remain within an acceptable load range, the springs support the load; but if it's forced to take on more than the rated load, the caster will compress, creating a hard stop. 

During a hard stop, the foot doesn’t clear the floor, rendering the cart or dolly immovable. To ensure the caster doesn’t compress prematurely or not enough during use, consider your minimum and maximum load for smoother and noiseless movement during travel. 

Spring-Loaded Casters with Customer Satisfaction Guaranteed!

Sometimes, determining proper deflection from spring-loaded casters requires an exact science that only 150 years of experience can provide. Our experienced team of caster professionals understands you shouldn’t choose casters solely based on appearance, which is why we have an extensive and unparalleled inventory that guarantees we’ll find exactly what you’re looking for. 

We’ll consider your load and equipment type, material preferences, and environment, whether you’re looking for caster wheels for outdoor use or indoor assistance. Using this information, our experts will determine the appropriate wheel height and diameter, tread type, and, most importantly, spring-loaded caster types according to deflection abilities. 

Despite your caster needs, Caster Central in Pembroke, MA, is your one-stop shop with all the top brands, like Shepherd, Jarvis, and Faultless. For a risk-free, 100% customer satisfaction guarantee or for answers to your burning questions about shock loading, call 1-800-445-4082 for assistance today!