coefficient of thermal expansion – A measure of the fractional change in size of an object per degree change in temperature at constant pressure.

Typically when discussing precision engineering, we mean the coefficient of linear thermal expansion, but there are also volumetric and area coefficients. On Practical Precision, unless otherwise specified, CTE refers to the coefficient of linear thermal expansion.

Material properties and thermal properties in particular tend to vary with temperature. Coefficient of thermal expansion tends to vary directly with temperature.


On Practical Precision, coefficient of thermal expansion is represented in formulas by the symbol α.

In text, the abbreviation CTE may be used.


SI: 10-6/K or 10-6/°C
English: 10-6/°F

See also

Differential thermal expansion

Related articles

Material selection for kinematic mount design

External references

Thermal expansion on Wikipedia

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