FAI First article inspection (FAI)
First article inspection (FAI) · Inspección y ensayos · ISO 1101 + ASME Y14.5
Example in plan
How to interpret it
On the drawing, “FAI per AS9102 / customer drawing before production run” states a first article inspection (fai) requirement.
What controls
Complete verification of the first part produced under a given set of conditions, checking every characteristic on the drawing and the associated documentation (material, heat treatments, special processes) before series production is authorized. It is not just another measurement: it is a gate. It is repeated whenever something changes that could affect the result: drawing revision, machine, tooling, material supplier or an extended process shutdown.
How to verify
Everything dimensioned is measured, with the instrument suited to each tolerance: conventional gauging for individual dimensions, CMM for GD&T and profiles, profilometer for surface finish, hardness tester for heat treatments. Each result is recorded with its instrument and calibration ID. Whatever is not measured on the part is demonstrated with documents: material, heat treatment and coating certificates, plus non-destructive testing reports if the drawing calls for them.
Common mistakes when interpreting it
- Making the first article under special conditions that are not those of the production run.
- Treating it as a dimensional check and forgetting the documentation side, which is half the requirement.
- Continuing production while the first article is awaiting approval.
How to get it in the workshop / if it comes out of tolerance
Prepare the report with the characteristics numbered on a copy of the drawing (ballooned), because the report is organized by those numbers and that way nothing is left unmeasured. The first article must come from the production process, with the actual production tooling and parameters: a part made “with extra care” just to pass first article represents nothing. Until it is approved, the run is not released, and that includes not continuing to machine parts “to get ahead”.
If a characteristic is out of tolerance, the process is corrected and the part and its verification are redone; it is not approved “with remarks” unless there is a formal concession. If the part is good but the report is incomplete, the first article is not approved either: evidence is missing. And if the drawing changes revision partway through a run, a new verification must be considered, even if the change looks minor.
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