For your consideration: 6 critical factors

Casters and wheels come in a various shapes, sizes and materials to match unique performance requirements. Some roll on tracks and temperatures up to 500 F. Others bear 40,000-pound loads inside and outside the factory. Choosing the right one will prevent downtime and excessive maintenance.

1. Rollability: it's all in the ergonomics

Ergonomic considerations are always top of mind. As the U.S. workforce ages and becomes heavier, it becomes more susceptible to workplace injuries. That's why employers seek tools and equipment, such as casters and wheels, to reduce stress on joints, prevent back injuries, and better accommodate staff.

Wheel size is the single biggest factor in rollability. Larger wheels are easier to push or pull under load. Even when wheel capacity well exceeds what the load requires, larger diameters help keep workers safe.

Test data is available to determine what size and tread type is best for any given load and ergonomic parameters. It's also true that harder wheels are generally easiest to move, but they can also create noise problems. Hamilton offers many polyurethane tread types to choose from, some specifically aimed at ergonomics. If load cushioning is critical, there are softer treads available. And, spring-loaded casters that provide cushioning without sacrificing ergonomics.

2. Capacity: avoid heavy miscalculation

What's the weight of the load plus the cart, trailer or AGV? What about the possibility of overload, shock loading, abuse or poor floor conditions? It may seem obvious to divide the maximum load weight by four (or however many casters or wheels), but this can lead to heavy miscalculations. Why? Because most loads don't maintain an even weight across the length and width of the vehicle. An off-center load could overload even the most durable casters.

3. Shock loading: prepare for impact

Shock loading occurs when a load is dropped onto the trailer. Or when a rig rolls over a bump, like a concrete joint, door jam, dock plate or leveler. In some cases, shock loading can force a wheel to bear more than three times the weight of the load.

Uneven floors, slopes, ramps or inclines can cause shock loading when one or more wheels lose contact with the floor. In these cases, the remaining wheels must carry the entire load.

4. Operating environment: temperature, noise, moisture and more

Where's it rolling? Environmental conditions must be considered when choosing a caster or wheel. For example, if excessive noise is an issue, Hamilton offers quiet-rolling wheels with high load capacities.

What about the temperature? Extremely hot or cold applications may require special caster and wheel materials, and bearing lubricants, to withstand the conditions.

Moisture can also wreak havoc on metal parts, including bearings, and also on some wheel materials such as polyurethanes. Chemicals present either on the floor or in the work environment require wheel and caster materials. Excessive dust or dirt? We suggest casters and wheels with sealed bearings. Continuous-duty applications are best suited to certain bearing types in the wheels.

5. Abuse: know your crew's tendencies

Abuse takes a toll on casters. We like to believe that everyone uses them as intended, but we also understand that's not always the reality. Sometimes workers move too quickly, take short cuts, or even take out frustrations on them. Keep this in mind when selecting equipment.

6. The effect of floors on wheels, and vice versa

Poor floor conditions can cause a caster or wheel to fail, but don't underestimate the effect wheels can have on floors, too. Very hard wheels, such as cast iron or forged steel, roll easily and carry higher capacities than resilient tread wheels. But, they can damage concrete floors and lead to costly repairs. Most resilient wheels absorb chips and metal shavings into their treads. These can dislodge in other parts of the facility and create housekeeping challenges or hazards. Certain resilient treads such as those found on Ergo-Glide and ErgoTech wheels are specially formulated to repel foreign objects and debris (FOD).