Get in touch with Zhenling Company
PMMA Thermal Drift Against Your Tolerance
Enter the feature, the tolerance you intend to call out, and the temperature difference between where the part is made and where it is inspected. The tool returns the uncorrected movement and tells you whether that tolerance can be judged without a stated reference temperature.
The dimension carrying the tolerance
Half the total band
Shop floor against inspection room
Take the exact value from your datasheet
uncorrected movement over the stated temperature difference
| Quantity | Value |
|---|---|
| Drift as a share of your tolerance band | |
| Temperature difference that alone consumes the whole band | |
| Same feature in steel, for comparison |
If you intend to hold this tolerance, the drawing has to state
- Reference temperature — 20 °C is the international reference for dimensional measurement, per ISO 1 and the ASME Y14 family
- Whether temperature correction is applied, and with which expansion coefficient
- Soak time before measurement
- Measurement method and its uncertainty budget
- Which named features the tolerance applies to
- Free state or restrained
Thermal movement is not an argument that tight tolerances are impossible — correction to the reference temperature is exactly what standard practice exists for. It is an argument that a tolerance figure quoted without those conditions cannot be judged. Coefficients vary by grade and additive package; use your material datasheet for marginal dimensions.
![Shop-Floor Carbon Steel CNC Machining Guide [2026]](https://zhenlingmetal.com/wp-content/uploads/2026/08/carbon-steel-cnc-machining-handbook-r2-featured-150x150.png)
