What is Thermal Conductivity?

In physics, thermal conductivity (often denoted k, λ, or κ) is the property of a material to conduct heat. It is evaluated primarily in terms of Fourier’s Law for heat conduction.

Heat transfer occurs at a higher rate across materials of high thermal conductivity than across materials of low thermal conductivity. So materials of high thermal conductivity are widely used in heat sink applications, and materials of low thermal conductivity are used as thermal insulation. Thermal conductivity of materials is temperature dependent. The reciprocal of thermal conductivity is called thermal resistivity.

Thermal conductivity is important in material science, electronics, and insulation, especially where high operating temperatures are achieved. The thermal conductivity of materials varies widely, and here is a list.  The figures should be considered approximate due to the uncertainties related to material definitions.