Steel Temperature Expansion Calculator
See how far steel and other metals expand across a temperature range — a lookup view rather than a single calculation. Pick a material and a length, and read the expansion at every service temperature from ambient upward, so you can size expansion gaps, slotted holes and pipe loops at a glance.
Expansion across a temperature range
| Service temp | ΔT | Expansion | Per metre | Final length |
|---|
Linear expansion ΔL = α L ΔT using near-ambient coefficients. Above roughly 300 °C the coefficient rises, so treat high-temperature rows as indicative.
Need a single figure for one specific temperature change, in any unit? Use the thermal expansion calculator.
Why expansion matters
A 10 m carbon-steel member heated from 20 °C to 60 °C grows about 4.8 mm. Restrain that movement and you generate large thermal stress instead — roughly 2.4 MPa per °C for fully restrained steel. That is why bridges have expansion joints, pipe runs have loops or bellows, and long cladding rails use slotted holes.
Frequently asked questions
How much does steel expand per metre per degree?
About 0.012 mm per metre per °C for carbon steel. Over a 100 °C rise that is 1.2 mm per metre.
What stress does restrained expansion create?
For fully restrained carbon steel roughly 2.4 MPa per °C (E x alpha = 200,000 x 12e-6). A 50 °C rise can therefore generate about 120 MPa.
Which steel expands least?
Among common alloys, ferritic stainless 430 (10.4) is lower than austenitic 304 (17.3). For true dimensional stability, Invar 36 at 1.2 is in a class of its own.
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Steel Temperature Expansion Calculator
Calculate the thermal expansion or contraction of steel elements due to temperature changes, essential for engineering design and construction applications.
Thermal Expansion Results
Thermal Expansion Visualization
Thermal Expansion Reference
Thermal Expansion Formulas
Linear expansion: ΔL = α × L₀ × ΔT
Area expansion: ΔA = 2α × A₀ × ΔT
Volume expansion: ΔV = 3α × V₀ × ΔT
Thermal stress: σ = E × α × ΔT
Where:
α = Coefficient of linear thermal expansion
ΔT = Temperature change
E = Young's modulus (≈ 200 GPa for steel)
Thermal Expansion Coefficients for Steel
| Steel Type | Coefficient (α) in 10⁻⁶/°C | Typical Applications |
|---|---|---|
| Carbon Steel | 11.7 | General construction, bridges, buildings |
| Mild Steel | 13.0 | Common structural steel, general fabrication |
| Stainless Steel 304 | 10.8 | Food equipment, kitchen fixtures, chemical tanks |
| Stainless Steel 316 | 16.0 | Marine applications, chemical processing |
| Structural Steel | 14.0 | Building frames, columns, beams |
| Tool Steel | 12.0 | Cutting tools, dies, industrial machinery |
| Low Expansion Steel | 10.0 | Precision instruments, measuring tools |
Engineering Considerations
- Expansion Joints: In long steel structures, expansion joints should be provided approximately every 30m (100ft) to accommodate thermal movement.
- Clearance Requirements: For steel elements that will experience temperature changes, provide approximately 1.5mm of clearance per meter of length for every 100°C temperature change.
- Thermal Bridging: When different materials connect, their different expansion rates can cause stresses at connection points.
- Pre-heating: For precision fits, components may need to be heated or cooled before installation to achieve the correct dimensions after reaching operating temperature.