The thickness ratios of the components can be selected according to the application requirements. The two outer layers usually have the same thickness.

Thermostatic bimetals are composite materials consisting of two or three layers of materials with different coefficients of thermal expansion. They are usually bonded together by cladding. If such a material part is heated either directly through current flow or indirectly through heat conduction or radiation, the different expansion between the active (strong expansion) and passive (low expansion) layer causes bending of the component part.

Table 5.23: Partial Selection from the Wide Range of Available Thermo-Bimetals

===5.4.1 Design Formulas===