Casters are likely one of the best inventions in the supply and packaging businesses. Whether you're using them on a kitchen cart or an industrial container that you need to push along a floor, the small wheels make the movement so much easier. Fewer people need to help out, and those who are moving the containers are at a lower risk of sustaining a stress injury (though the risk still exists, and your company needs to take appropriate safety measures). The type of caster you choose when ordering a container changes the casters' effects on your ability to get that container from one end of the building to another.
Wider, or thicker, casters offer more support for larger weights. With thicker posts and a thicker wheelbase, the weight of the items in the container is more evenly distributed—even a small amount of extra wheel surface makes a difference. The casters are less likely to buckle under a heavy weight.
At the same time, thinner casters are excellent for lighter loads. There is less drag on the floor surface because there is less wheel surface creating that drag. Turning is also easier as less friction occurs between the wheel and floor. (Whether the caster has a tread or a smooth surface will also affect this.)
Smaller wheels offer better control. Because each rotation of the wheel makes the wheel travel a shorter distance, it's easier to stop a container or make sudden turns, especially if the container's load is light. Heavier loads will, of course, make the container more difficult to control simply because of the weight pressing down toward the floor. But even if heavier containers are more difficult to turn, they can be easier to stop when the wheels are smaller.
Larger wheels, regardless of width, cover more ground with each rotation and can build up a lot of momentum. These make containers relatively difficult to turn or stop compared to containers with smaller wheels. Again, weight comes into play. If you need to transport extremely heavy items, the container may be difficult to turn regardless of the wheels.
If you need to wheel the container over uneven ground, such as dirt paths or concrete with a lot of cracks, you'll want bigger and thicker wheels. These are much less likely to catch on those cracks or on bumps in the surface of the ground. When you move a container, you don't want to have to keep stopping to force the container past a crack in the concrete, and bigger, wider wheels are better for rougher terrain.
The right container casters will make work go so much more smoothly. Look for casters that are appropriate to the terrain, load, and level of control that the container will be exposed to.