Counterweights are used in a wide variety of applications. They are needed to offset or balance a heavy object, often one that is in motion. Common uses for counterweights include the use on bascule bridges, elevators, and cranes as well as other types of heavy equipment or machines.
Weight and Size
Lead counterweights offer several different advantages over counterweights made of other types of alloys. The use of lead provides a heavier object with a smaller physical size, limiting the space requirement for the weight. In most cases, the size of a lead weight will be over 40% less than the same design in iron to create the effective balance.
In counterweights, the size is relevant given the space available for the counterweight. This is particularly important for elevators and cranes where the counterweights may need to have significant weight to offset the weight of the equipment as well as the load capacity.
Limited Reactivity
Lead is not as reactive or corrosive as other types of the heavy alloys, particularly when compared to iron. This means that lead counterweights won’t form iron oxide or rust. Iron will rust significantly, which leads to the common red staining and flaking of the surface of the metal.
It is possible for lead counterweights to form lead oxide, which can have a grayish tinge, but it looks more like a powdery substance. It will also easily rinse off and is not prone to the pronounced staining seen with iron. This saves the added step of applying a plating or finish in the lead, saving on the cost of manufacturing the counterweights.
For safety from lead exposure, counterweights are often coated with a powder coat or an epoxy paint. This is particularly important if the lead is used in marine or outdoor applications.
