Coefficient of linear expansion

Coefficients of linear expansion

for some common solids

Material(per °C)

aluminum0.000025

brass0.0000189

copper0.000017

lead0.000029

cast iron0.000011

platinum0.000009

glass0.000009

Pyrex glass0.000003

steel0.000012

concrete0.000012

Invar (nickel steel)

Different materials expand by different amounts. Just how much a particular material expands depends on the forces of cohesion between neighboring atoms or molecules. If these forces are strong, the material can only expand slightly for a given rise in temperature. A metal such as lead which has a low melting point and is relatively easily compressed, expands a great deal for a given rise in temperature.