Thermal expansion and fit
Compare a part and opening as temperature changes, showing clearance or interference. Change the inputs to update the chart or diagram.
Your inputs
The editable example is illustrative. Enter your own dimensions, operating data, prices, and fees. Results update as you edit.
Calculations run in your browser. Inputs are not saved or sent to analytics.
How it works
- ΔT = −
- ΔL = L₀ × α × ΔT; Final clearance = (1 + × ΔT) − (1 + × ΔT)
Input and formula key
Your result
Complete the inputs to see your result.
Assumptions and limitations
Assumes free, uniform linear expansion with constant coefficients and a shared temperature change. Enter coefficients for the actual materials and range. Constraints, stress, gradients and structural suitability are excluded. Positive gap means clearance. Example: 100 mm at 23 µm/(m·K) inside 100.2 mm at 12 µm/(m·K), heated 20→80°C, leaves 0.134144 mm.
Sources
- NIST — thermal effects in dimensional metrology Sources reviewed: 2026-10-22
