Engineering tool · V0.6

Thermal Fit Calculator

Estimate how a hole and shaft change with temperature using linear thermal expansion, and see the resulting clearance or interference at operating temperature.

Hole diameter at reference temperature (mm)

Shaft diameter at reference temperature (mm)

Hole material α (µm/m·K)

Shaft material α (µm/m·K)

Reference temperature (°C)

Operating temperature (°C)

Hot hole diameter—

Hot shaft diameter—

Resulting diametral clearance—

Enter values to calculate.

D₁ = D₀ × (1 + α × ΔT)

Linear coefficients are approximate and can vary with alloy, polymer grade, fiber direction and temperature. This calculation ignores gradients, constraint, elastic deformation and heat-transfer transients.