When it comes to your material handling operations, having the right steel caster wheels can make all the difference. You might not be looking to reinvent the wheel, but you do want one that offers the right mix of longevity, smoothness and strength that's essential for a wide variety of carts. The following offers an in-depth guide on choosing the best steel casters for your warehouse environment.
Choosing the Right Wheel Diameter
A material handling cart's performance depends largely on the size of its caster wheels. A small caster diameter makes a cart easier to maneuver through lower threshold door openings and other low-clearance areas but more difficult to climb over debris. Whereas a large-diameter wheel requires less force to roll over obstacles. but can easily raise the cart's center of mass, making it more likely to tip over when transporting heavy materials. This can pose a problem for tall enclosed carts.
According to the Fabricator's Tim Heston, wheel diameters for most in-plant applications usually range from 6 inches to 12 inches in diameter, with 8-inch diameter wheels being the most popular. The heavier the load that's being moved, the larger the wheel diameter should be to accommodate the forces required to move the load.
Metal vs. Polyurethane
All-steel caster wheels are highly durable and even ideal in applications that utilize track systems, such as a heavy-duty material handling cart made for transporting heavy goods and materials. However, a steel caster can cause severe damage to concrete floors, making them undesirable for most in-plant operations. Steel casters may also require more effort to move in manual push-pull applications.
In contrast, a steel caster wrapped with a polyurethane tread requires less force to manually move, thanks in large part to the traction provided by the polyurethane compound. The tread also gives both the caster and the cart a small degree of shock resistance when traveling along rough concrete surfaces, depending on the amount of deformation designed in the material. Spring-loaded wheel casters can provide further suspension for bumpy and uneven surfaces
The vast majority of caster wheels used in warehouses and plant environments feature polyurethane-covered wheels in varying degrees of hardness, depending on the application:
- Harder polyurethane tread types offer lower rolling resistance, which translates into lower effort in manual push-pull applications. However, the downsides include greater noise and a propensity for getting stuck on debris and within floor gaps.
- Softer polyurethane tread types suppress noise while allowing for easier movement on debris-laden and bump-riddled surfaces. As a downside, carts fitted with soft polyurethane treads take more effort to move around than those featuring harder tread surfaces.
Tread thickness is also a major factor in choosing the right caster wheel. Polyurethane-lined wheels with thick tread require more effort to roll, but they also provide better resistance to shock and debris impacts.
There are plenty of other factors that may influence the type of caster wheels you'll use for your material handling operations:
- Swivel mechanism types – Most caster wheels use kingpins to hold the wheel's various components together. It's one of the oldest and often tried-and-true methods of holding a caster swivel section together. However, the rivet or bolt used for this purpose is a common fail point for most casters. Kingpinless designs provide better load distribution and greater reliability but at the cost of adjustability.
- Swivel lead – The longer the distance between the wheel's center and that of the swivel section, the easier it becomes to turn the cart. However, heavy loads can cause the caster assembly to break if the swivel lead is too long.
- Contact patch – The wider the wheel and the heavier the load, the larger the contact patch becomes. A large contact patch can make it more difficult to turn and move carts carrying heavy loads. A heavy-duty twin caster design can reduce turning effort and minimize the scrubbing effect that occurs as a caster wheel changes direction.
It's important to keep the above in consideration as you choose your caster wheels. The right wheel can help improve the overall efficiency of your material handling operations. You can find various caster wheels at sites like http://www.garlandsinc.com/.