Differences between a steel and an aluminium Load Cell

There are load cells of the same shape appearance, but made of different materials, as steel or aluminium. Both may even have similar accuracy, repeatability and linearity characteristics but not the same mechanical resistance to overload, shocks or fatigue.

In order to reduce costs in manufacturing, different aluminium alloys may be used and they bear good results in regards to accuracy but they have the disadvantage that they are much weaker than the ones manufactured of steel alloy, in the sense that if certain stress levels are exceeded, the cells are more easily deformed and undergo displacements of the output signal. Therefore, they are also weaker in front of overloads and much more sensitive to shocks. Furthermore, they wear out more easily with dynamic loads and last less.

Therefore, in case the choice is an aluminium load cell, precautions should be increased in overload stoppers and choose load cell nominal capacities with a higher over-dimension in respect to the applied load than for a steel load cell.

The aluminium load cells are usually used in great consumption applications because they save costs in great series, where the scales designing team may have studied, project, over-dimension and test this solution properly in order to avoid problems.

For industrial weighing processes, of little production, it is safer and more reliable to directly use versions of cells made of high resistance steel alloys.

Also, to mention that there exist other materials with a very high resistance to fatigue, as the Beryllium-Copper, but very seldom used due to its high cost. Currently, they are only justified in high fatigue applications.