There are several factors to consider when choosing the right caster for your conveyor system.  There are as many types and configurations of conveyor systems as there are uses.  You should never select on the basis of load capacity alone.   Capacity ratings do not take into account the effort required to manually move a load.

Most conveyor applications do not require conveyor to be moved very often.  For that reason a wheel with a hard rolling surface is the best choice to avoid the wheel surface from developing a flat spot. 

If the conveyor has 4 casters with a total weight less than 1000 LBS select a hard tread wheel from Model 3.  If the total weight exceeds 1000 LBS on 4 casters select a polyolefin wheel from Model 9.

Material handling systems, storage and handling systems, material flow, warehouses, factories, and distribution centers.