Printable reference · V0.6
Fits & Thermal Effects Reference
A compact reference for clearance, transition and interference fits and differential thermal expansion.
Fits & Thermal Effects Reference
| Condition | Limit logic | Typical intent |
|---|---|---|
| Clearance fit | Minimum hole remains larger than maximum shaft | Sliding, rotation, assembly without press |
| Transition fit | Tolerances can create either small clearance or small interference | Accurate location with variable assembly feel |
| Interference fit | Maximum hole remains smaller than minimum shaft | Retention / torque transfer by elastic contact |
Thermal reminder
D₁ = D₀ × (1 + α × ΔT)
Different materials can change a fit significantly with temperature. Check the hole and shaft separately using appropriate coefficients and operating temperatures.
Review prompts
- Is the fit defined at manufacturing temperature or operating temperature?
- Do surface finish and form error consume meaningful clearance?
- Can assembly force or contact pressure damage either component?
- Will repeated assembly cause wear/fretting?
- Do plating/coating thicknesses alter effective limits?
- Are polymer creep or moisture effects relevant?
DIVE-LD Engineering Learning · Educational reference only. Confirm project-specific requirements, governing standards and supplier capability before release.