Plating, Anodizing & Surface Treatment worked example

Acid Etch Rate at 68% target acid-etch conformance: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target acid-etch conformance to 68%, then walk the calculation through step by step. Estimate acid etch rate for plating, anodizing and surface treatment using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.

The inputs for this scenario

  • Parts showing out-of-spec acid etch: 8 count (held at the documented default)
  • Total parts inspected in the lot: 250 count (held at the documented default)
  • Target acid-etch conformance: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Acid etch rate = acid etch rate count ÷ total acid etch rate population × 100.
  • Acid etch rate works out to 3.2 % at these inputs, and this is the headline figure for the scenario.
  • Acid etch rate gap to target works out to 64.8 points at these inputs.
  • Acid etch rate count works out to 8 count at these inputs.
  • Total acid etch rate population works out to 250 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target acid-etch conformance sits at 95% and the headline result is 3.2 %, this scenario lands almost exactly on the baseline at 3.2 %.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to target acid-etch conformance, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. A percentage says nothing about severity or defect type; eight lightly smutted parts and eight deeply pitted parts read the same 3.2%.

Results at a glance

  • Acid etch rate: 3.2 % (headline result)
  • Acid etch rate gap to target: 64.8 points
  • Acid etch rate count: 8 count
  • Total acid etch rate population: 250 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Acid Etch Rate calculator, set target acid-etch conformance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.