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First Article Inspection Report for Custom Metal Parts: A Practical Buyer Checklist
Direct answer: A first article inspection report for a custom metal part should connect every reported result to the approved part number, drawing revision, material and process requirements, and a clearly identified sample. A useful report normally includes a ballooned drawing or characteristic list, actual measured results, acceptance limits, measurement methods where relevant, material and process certificates when required, nonconformance status, and formal review or approval responsibility.
First article inspection, in-process inspection, and final inspection have different purposes. The first article confirms that the released definition can be produced and verified. In-process inspection controls variation while production is running. Final inspection confirms that the completed lot meets the agreed release requirements.
1. What is first article inspection?
First article inspection (FAI) is a documented verification of one or more representative parts produced from the intended manufacturing route. It compares the completed part with the current controlled requirements before routine production is accepted. The scope depends on the drawing, process, customer requirements, and project risk; it should never be assumed from the phrase FAI required alone.
2. When should an FAI be requested?
An FAI is commonly requested for a new part, new tooling, a significant engineering change, a manufacturing-location change, a long production interruption, or another change that could affect form, fit, function, material, or process output. The buyer and supplier should agree whether the requirement is a full FAI, a partial FAI limited to changed characteristics, or another approval method.
3. Confirm the controlled drawing and revision first
The report must identify the governing part number, drawing number, revision, and any referenced specifications. The physical sample, measurement results, certificates, and approval record should all point to the same released definition.
Part name and part number
Drawing number and revision
Purchase order or project reference
Sample or lot identification
Manufacturing location and process route, when required
Date of manufacture and date of inspection
For change-control principles, see Engineering Drawing Revision Control for OEM Metal Parts.
4. Use a ballooned drawing or characteristic list
Each dimensional, material, finish, marking, and documentation requirement should be traceable to a numbered characteristic. A ballooned drawing makes it easier for engineering, quality, and the supplier to review the same requirement without relying on different interpretations.
Reference dimensions and informational notes should be identified as such. They should not be turned into independent acceptance criteria unless the released definition requires it.
5. Report actual results, not only pass or fail
For measurable characteristics, record the actual result together with the nominal requirement and tolerance or limit. A simple OK may be suitable for some visual, marking, or documentation checks, but it is usually not enough for critical dimensions when the buyer needs evidence of the measured value.
| Report field | What it should show | Why it matters |
|---|---|---|
| Characteristic number | Direct link to the ballooned drawing | Creates one-to-one traceability |
| Requirement | Nominal value, tolerance, specification, or note | Defines the acceptance basis |
| Actual result | Measured value or documented observation | Provides objective evidence |
| Method | Gauge, micrometer, CMM, functional gauge, test, or certificate | Supports review of measurement suitability |
| Status | Accepted, rejected, or pending disposition | Prevents unresolved results from being overlooked |
6. Match the measurement method to the characteristic
The most sophisticated equipment is not automatically the best method. Select the method based on feature geometry, tolerance, accessibility, datum structure, repeatability, and the decision the measurement must support. A CMM may be appropriate for geometric relationships and datum-based measurements, while micrometers, calipers, thread gauges, surface-roughness instruments, optical systems, or functional gauges may be more suitable for other characteristics.
Review Castle's published quality control and inspection information when defining project-specific documentation.
7. Include material and special-process evidence when required
Dimensional results alone do not confirm material grade, heat treatment, coating, plating, passivation, welding, or other controlled processes. The FAI package should include or reference the agreed material certificates, process certificates, test reports, or certificates of conformity. Requirements must be stated in the RFQ and purchase documents so that the supplier can plan them before production.
8. Record deviations and open items visibly
A result outside the released requirement should not be hidden by averaging, rounding, or changing the report. Record the actual result, identify the affected characteristic, and route the deviation through the agreed engineering and quality approval process. Approval of one deviation should not silently change the drawing or become a permanent production rule.
9. Connect FAI to in-process and final inspection
FAI is not a substitute for production control. Its findings should help define the control plan: which characteristics are checked during setup, which are monitored during production, which require final verification, and what sampling or reaction plan applies. Critical interfaces, special characteristics, process-sensitive dimensions, and known risks often need more attention than low-risk general dimensions.
10. Define approval responsibility before submission
The RFQ or quality agreement should state who prepares the report, who reviews it, whether physical samples are required, where digital records are submitted, and whether production may begin before written approval. These details prevent a technically complete report from becoming an administrative bottleneck.
Compact FAI package checklist
Current part number, drawing number, and revision
Identified representative sample and manufacturing lot
Ballooned drawing or numbered characteristic list
Nominal requirements, tolerances, and actual results
Measurement or verification methods where relevant
Material, heat-treatment, finish, and special-process records when required
Clear nonconformance and deviation status
Inspector, date, review status, and buyer approval responsibility
Defined transfer of critical characteristics into in-process and final inspection
Frequently asked questions
Is first article inspection the same as final inspection?
No. FAI verifies that the released design and intended manufacturing route can produce a conforming part with documented evidence. Final inspection checks the completed production lot against the agreed release requirements.
Should every drawing dimension be included in an FAI report?
The agreed scope should cover all applicable requirements unless the buyer authorizes a defined partial FAI or another documented exception. Reference dimensions and informational items should not be converted into new acceptance requirements.
What is a ballooned drawing?
A ballooned drawing assigns a number to each reported characteristic. The same number appears in the inspection report, connecting every result to its drawing requirement.
Can an FAI report contain only pass/fail results?
Some visual or documentary checks may use pass/fail status, but measurable characteristics should normally show actual results when objective dimensional evidence is required.
When is a partial FAI appropriate?
A partial FAI may be appropriate after an approved change that affects only defined characteristics or processes. The buyer and supplier should document the scope and the reason for limiting the inspection.
What should buyers include in the RFQ?
State the FAI scope, report format, number of samples, certificate requirements, approval responsibility, and whether production may proceed before approval. Use the Custom Metal Parts RFQ Checklist to align the complete package.
Plan inspection evidence before production
A useful first article package starts with one controlled definition and ends with clear production controls. To discuss a custom metal-part project, send the current drawings and quality requirements through the Castle Mechanical contact page.