Thermal expansion converter
Convert expansion coefficients between metric and Fahrenheit forms, and see how far a 10 m beam moves across the seasons.
That's about the same as steel. A 10 m beam would move about 4.8 mm over a 40 °C swing.
What it means
How much does it move?
Linear expansion. Volume expansion is roughly three times the linear figure for solids.
Every unit
Your coefficient in every unit
Learn
Three things worth knowing
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Steel moves 12 µm per meter per degree
A 10 m steel beam grows about 5 mm over a 40 °C swing. Bridges have expansion joints for exactly this reason.
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Why rails used to clack
Old track was laid in short lengths with gaps for expansion, which made the rhythmic clack. Modern welded rail is pre-stressed instead, and runs silent.
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Per kelvin or per degree Fahrenheit?
A Fahrenheit degree is smaller, so the coefficient is 1.8 times smaller too. Mixing them up under-predicts movement by nearly half.
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Popular expansion conversions
Background
About thermal expansion
The coefficient says what fraction of its length a material gains per degree, usually quoted as ppm per kelvin. Steel is 12, aluminum 23, and Invar barely 1.2, which is why Invar is used in precision instruments.