TENTE explains the load capacity of wheels and castors and the factors that influence this.
Load capacity of wheels and castors
The loads that machines or transport equipment can withstand depend, among other things, on the load capacity of the wheels and castors. When purchasing wheels or castors, therefore, it is vital to take this property into consideration. In order to determine the load capacity required for the equipment, certain factors must be known: on the one hand, the weight of the equipment itself and the maximum weight of the applied load, and on the other hand, the number of wheels and castors to be used. In order to ensure that the castors can withstand the loads in the long term, the total number of castors assumed for the calculation is reduced by one. This takes into account that the weight of uneven floors is not always evenly distributed.
The load-bearing capacity of the individual castors and wheels is determined under ideal conditions, i.e. on level ground, at a specified temperature of approx. 15 - 28°C, moving straight ahead at walking speed. Since the actual conditions of use are usually different, an additional safety factor should be included in the calculation. The more the operating conditions differ from the test environment, the larger the safety factor needs to be.