Values of Thermal conductivity for some materials:

Substance	k (W/mK)
Aluminium	………………………………………228
Copper	………………………………………386
Brass	……………………………………110.7
Mild steel	……………………………………..53.6
Glass wool	……………………………………0.038
Asbestos	……………………………………..0.16
Air	……………………………………0.022
Rubber	……………………………………0.163
Fire brick (Kaolin)	……………………………………0.089
Mica	……………………………………0.582
Teflon	……………………………………0.350
Cotton fibers	……………………………………..0.06
Wood	……………………………………0.059