What is the expansion rate of a steel push-rod to a aluminum push-rod?

The expansion rate of materials is typically measured by their coefficient of thermal expansion (CTE). Steel has a CTE of approximately 11-13 x 10^-6 /°C, while aluminum has a higher CTE of about 22-24 x 10^-6 /°C. This means that, for a given temperature increase, aluminum will expand roughly twice as much as steel. Consequently, in applications involving temperature changes, aluminum push-rods will experience greater dimensional changes compared to steel push-rods.