Metals, Steel, Aluminum & Coil Processing worked example

Metal Thickness Window with thickness tolerance band of 2 mils: a worked example

Suppose thickness tolerance band falls to 2 mils. This page works the full calculation at that level so you can see exactly which result moves and by how much. Check whether a gauge reading fits inside the thickness tolerance band by subtracting the measured deviation and a reserve buffer from the allowed band.

The inputs for this scenario

  • Thickness tolerance band: 2 mils (the input this scenario stresses; the baseline uses 4)
  • Measured deviation: 2 mils (held at the documented default)
  • Reserve buffer: 1 mils (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Remaining tolerance = thickness tolerance band - measured deviation - reserve buffer.
  • Inside window works out to 0 outside at these inputs, and this is the headline figure for the scenario.
  • Nearest margin works out to -0 value at these inputs.
  • Lower limit works out to 2 value at these inputs.
  • Upper limit works out to 1 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where thickness tolerance band sits at 4 mils and the headline result is 0 outside, this scenario lands almost exactly on the baseline at 0 outside.
  • It subtracts the measured deviation and your reserve buffer from the tolerance band to report whether remaining tolerance is positive (inside) or negative (outside). When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Inside window: 0 outside (headline result)
  • Nearest margin: -0 value
  • Lower limit: 2 value
  • Upper limit: 1 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Metal Thickness Window calculator, set thickness tolerance band to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.