What Is Caster Rollability and Why Is It Important?
The primary role of casters is to mobilize chairs, toolboxes, carts, dollies, furniture, and other otherwise immovable products and equipment. Installing these mechanisms gives everyone, from workers at manufacturing plants to homeowners during the moving process, the ability to transfer heavy items. However, caster rollability affects how the products function and their effectiveness on the job.
No two wheels are the same since some work better than others under different circumstances, depending on numerous factors like size and materials. Below, our experts delve further into those factors. We’ve dedicated over 150 years to studying and perfecting casters and their handling abilities, now giving you more than 2,500 caster wheels from Caster Central, so trust us with your rolling needs.
Why Does Caster Rollability Matter?
Rollability is the ease of caster movement, including maneuverability around corners, obstacles, and on certain surfaces, from water and oil-drenched to dirt and gravel.
To find the appropriate casters for you, determine the environment you’ll use them in so you understand what they must stand up against. Otherwise, the wrong casters lead to sudden stops and jerks, contributing to equipment and product damages alongside injuries to those nearby.
Some factors affecting rollability are wheel materials, size, and bearings alongside the floor type, load, and maintenance you provide it with.
1. Caster Materials
Hard wheel materials have a lower breakaway force rating than soft-wheel casters since they take less energy to start moving, especially on softer floors. That means they roll effortlessly on carpets, dirt, and grass while proving more durable and maintaining their shape over time.
Sustained rolling force averages half the breakaway force, meaning hard tread materials also have a lower sustained rolling force than soft tread materials. For instance, hard rubber (with a 2.4 breakaway and 1.2 in sustained), cast iron (with a 1.6 breakaway and 0.8 sustained), and phenolic resin (with a 2 breakaway and 1 sustained) maneuver easier than V-grooved and FW flanged with 11 breakaway forces.
However, soft tread materials are more shock absorbent since their extra cushion minimizes noise and vibrations and has higher caster rollability on mats and hard floors. Soft casters like mold-on rubber, mold-on polyurethane, and Advantage TPR are also known for their floor-protecting properties but need more frequent replacements than their hard tread counterparts.
2. Caster Size
Wheel size is just as vital as material type since caster diameter affects rollability. The larger the diameter, the more product comes in contact with the floor surface area, grounding the wheel better for easier maneuvering.
Larger wheels also work better than smaller ones in manufacturing, construction companies, and warehouses since they roll conveniently over debris. For instance, six-inch and eight-inch wheels are common in these environments, especially on dollies, carts, and other equipment.
However, you’ll need to reduce the caster diameter for smaller pieces, like toolboxes and small cabinets, to lower the standover height and create a minimal profile. Smaller diameters, around two inches, also create a lower center of gravity, making it more difficult for the appliance or equipment to topple, even in high-traffic areas or when traveling through rough terrain.
3. Bearings and Other Accessories
The caster bearings connect the wheel to the axle in the center, allowing them to move with little friction and enhancing caster rollability. If your bearings aren’t the appropriate shape, size, or material for the wheel, or if they are not properly maintained, they become more difficult to turn, affecting caster functionality.
For instance, caged roller bearings made from metal are ideal for heavy loads and provide inward thrust retention that lengthens their lifespan. On the other hand, plain bores are perfect for light-duty applications, and the design makes them slightly more durable. But if used alone, they don’t contribute to easy movement.
Although not water or chemical-resistant, roller bearings with a split metal outer cage are a top choice for their strength, durability, 2.5 MPH maximum speed, and 350-degree temperature tolerance. However, other components around the wheel also affect the caster, including the following:
- The swivel offset lets the wheel move in all directions rather than forward and back. But if the ball joint and caster center are further from the rivet and kingpin than they should be, it throws the balance between the load-bearing capacity and caster angle, breaking the caster yolk.
- Top plates attach the caster to the load-bearing product while protecting the wheel. However, a soft plate on rough terrain causes the material to dent and weaken, affecting its weight-bearing ability and caster movement.
- Rivets connect the top plates to the caster, undergoing a lot of force during operation and failing as the kingpin wears over time. Deterioration causes the caster to lose functionality, so consider kingpin-less casters and stronger steel rivets.
If your casters aren’t strong enough to handle a heavy load, the items you’re moving weigh down the wheels, requiring more force from you to move them. Each type of caster holds a different weight, depending on material makeup and dimensions, which determines your load capacity to improve rollability.
Take the total weight of your equipment fully loaded. Then, determine the number of casters you plan to use (usually two or four, depending on the equipment) and subtract one caster before dividing the weight by the caster number. This number gives you the minimum capacity load per caster:
- Under 350 pounds: 1-inch to 1.25-inch wide casters
- Between 350 and 1,250 pounds: 2-inch wide casters
- Over 1,250 pounds: 3-inch casters or larger
5. Floor Conditions
Again, soft wheel tread casters are best on hard surfaces like wood, concrete, and laminate. They maneuver more effortlessly on these flooring types than on soft terrain and are gentler on the surface, preventing damages like scuffs and dents and protecting your home or workspace. Contrarily, hard tread wheels provide easier caster rollability on softer surfaces like carpets, rugs, dirt, and grass.
However, you should also consider the condition your floors usually undergo. For instance, if water puddles or slick floors are common, you’ll need a water and steam-proof caster like cushion or hard solid rubber, but not all water-proof materials handle all residue.
Consider your caster type carefully if you work in a mechanic shop or other places where metal chips, oil, grease, or mild chemicals are evident. For example, while some casters, like high-modulus rubber, handle mild chemicals, water, and steam, it doesn’t fare well with oil and grease. Similarly, hi-temp resin is ideal for rooms and floors with extreme temperatures below -20 degrees and over 250 degrees.
Most casters, especially hard tread casters, are durable enough to handle most abrasions throughout their lifespan, requiring little to no maintenance. However, softer ones are more prone to damage or deflating prematurely if used excessively over rough surfaces, so clean your floors regularly and limit outdoor use.
Whether you have soft or hard tread casters, cleanings are vital, which includes dislodging particles trapped under the plate or between the swivel offset. Inspecting the swivel joint and lubricating the caster’s moving parts also ensure little friction and easier movement.
We Offer a Satisfaction Guarantee and the Widest Selection Available!
Have you ever had to go to several stores to find a product? At Caster Central in Pembroke, MA, that’s never an issue with our vast selection of over 2,500 caster types from top brands like Colson, Albion, and more. We’ll help you filter through the inventory, finding what you need, whether it's caster wheels for hardwood floors or soft terrain, so call 1-800-445-4082 to learn about caster rollability today!