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LINEAR THERMAL EXPANSION COEFFICIENT OF ALUMINUM ALLOYS

Aluminum has a relatively high linear thermal expansion compared to many steels and titanium alloys. The table below lists typical room-temperature CTE (α) values for commercially pure aluminum and common wrought/casting alloys in both 10⁻⁶/°C and 10⁻⁶/°F.

Formula. For a uniform temperature change, the change in length is \( \Delta L = \alpha \, L_0 \, \Delta T \). Use 10−6/°C or 10−6/°F consistently with ΔT.

For a general comparison of thermal expansion coefficients across metals, see the main reference page: Thermal Expansion Coefficient of Metals (Overview) .

Linear Thermal Expansion Coefficient Values for Aluminum Alloys
Metal or Alloy Temp. 10−6/°C 10−6/°F
Aluminum (99.996%) 20–100 °C / 68–212 °F 23.6 13.1
Wrought alloys
1060, 110020–100 °C / 68–212 °F23.613.1
2011, 201423.012.8
202422.812.7
221822.312.4
300323.212.9
403219.410.8
5005, 5050, 505223.813.2
505624.113.4
508323.413.0
5086 60–300 °C / 140–572 °F 23.9 13.3
515420–100 °C / 68–212 °F23.913.3
535723.713.2
6061, 606323.413.0
707523.212.9
Casting alloys
242.020–100 °C / 68–212 °F22.512.5
295.022.912.7
356.021.411.9
413.020.511.4
514.023.913.3
520.025.214.0

Why aluminum has a high thermal expansion coefficient

Aluminum expands more than many structural metals because of its face-centered cubic (FCC) crystal structure and relatively low elastic modulus. As a result, aluminum alloys typically have a linear thermal expansion coefficient around 22–25 × 10⁻⁶/°C, compared with about 10–12 × 10⁻⁶/°C for carbon steels.

Notes

  • Values are typical around 20–100 °C (unless stated otherwise) and may vary by temper, product form, and producer.
  • Use design allowables and material standards (e.g., ASTM) where required.

Related calculators & tables

Reference

  • Davis, J. R. Metals Handbook Desk Edition. ASM, 1998.