Calculating Load Capacity. The first step in figuring out how much each caster must support is to divide the total load by the number of casters. For a 4-wheel material-handling cart that must support 1,000 lbs., for example, dividing 1,000 by 4 gives a minimum load capacity of 250 lbs. per caster.

Iron Heavy-Duty Casters Nothing beats iron when it comes to force absorption and load-bearing. And, when you have cast iron caster wheels, you can get maximum weight-bearing. These weight casters are ideal for when you are moving large and heavy pieces of equipment.

Rubber wheels are softer and provide better traction on hard surfaces, making them ideal for smooth floors. However, they tend to wear out faster than polyurethane wheels and can become noisy over time. Polyurethane wheels are more durable and have a longer lifespan than rubber wheels.

Casters come in three weight ranges. Light duty casters are for loads of up to 500 lbs. Medium duty casters are for weights of between 501 and 2,000 lbs. And heavy duty casters are for weights of more than 2,000 lbs.