Last updated on August 31st, 2026 at 10:46 am
Get Rapid First Article Inspections at Approved Sheet Metal
A First Article Inspection (FAI) provides documented evidence that an initial production part or assembly conforms to the applicable drawing, specifications, and purchase-order requirements.
But not every project needs the same level of inspection. A customer may require a formal FAI, an AS9102 FAI, a dimensional inspection report, inspection of selected critical features, or simply verification of the first part produced.
One of the easiest ways to reduce unnecessary inspection time and cost is to define exactly what documentation you need before the job is quoted and manufactured.
FAI vs. First-Part Inspection vs. Dimensional Inspection
These terms are sometimes used interchangeably, but they can represent very different requirements.
| Inspection Type | What It Typically Means |
|---|---|
| First-Part Inspection | An initial manufactured part is checked to verify the setup and important dimensions before production continues. |
| Dimensional Inspection Report | Actual measurement results are documented for specified dimensions or characteristics. |
| First Article Inspection (FAI) | A documented verification of an initial production part or assembly against specified engineering and quality requirements. |
| AS9102 FAI | A formal aerospace First Article Inspection performed and documented according to AS9102 requirements when specified by the customer. |
Don't assume your fabricator knows which version you need. If a particular inspection report, format, or standard is required, identify it on the RFQ or purchase order.
3 Tips for Smarter and Faster First Article Inspections
1. Define the Inspection Requirement Before Quoting
The most important step is determining what type of inspection your project actually requires.
If you simply request an “FAI” without defining the requirement, the fabricator may need clarification before the job can be quoted or inspected.
Tell your fabricator whether you need:
- A first-part inspection
- Measurements of selected critical dimensions
- A dimensional inspection report
- A complete First Article Inspection
- An AS9102 FAI
- A customer-specific inspection form
- A ballooned drawing
- Material certifications
- Outside-process certifications
- A Certificate of Conformance
Defining these requirements during quoting allows the required inspection time, documentation, and quality processes to be planned before production begins.
2. Identify Critical Dimensions When a Full FAI Isn't Required
If your project does not require a complete FAI, identifying the dimensions that actually control fit and function can make inspection more efficient.
Depending on the part, critical characteristics might include:
- Hole patterns
- Formed heights
- Overall formed dimensions
- Mating surfaces
- Hardware locations
- Enclosure openings
- Datum-controlled features
- GD&T-controlled characteristics
- Features that locate the part in an assembly
This does not mean that certain manufacturing processes should automatically be excluded from inspection. A laser-cut hole, for example, still needs to be verified if it is a required characteristic on the specified inspection report.
If a complete FAI or AS9102-compliant report is required, the applicable characteristics must be documented according to those requirements.
3. Specify the Required Report and Documentation
Inspection requirements involve more than measurements.
If your quality system or customer requires a specific documentation package, communicate that requirement before the order is placed.
Depending on the project, the package may require:
- Ballooned drawing
- Recorded dimensional results
- Material certifications and traceability
- Special-process certifications
- Certificate of Conformance
- AS9102 forms
- Customer-specific inspection forms
- Part or lot identification
- Approval before the remainder of production continues
Documentation requested after the parts have already been manufactured can create problems if the required records, traceability, or inspection data were not established during production.
How GD&T and Tight Tolerances Affect FAI
Geometric Dimensioning & Tolerancing (GD&T) and tight dimensional tolerances are important tools for controlling fit, form, orientation, and location. They can also affect how a part needs to be inspected.
Tighter Tolerances Can Require More Inspection Resources
A tighter tolerance may require more capable measurement equipment, additional measurement points, more careful fixturing, or additional inspection time depending on the feature.
This does not mean tight tolerances should be avoided. It means they should be applied where the function of the part requires them.
GD&T Can Require Different Measurement Methods
Controls such as position, profile, flatness, perpendicularity, and parallelism may require different measurement strategies than simple linear dimensions.
The required inspection method depends on the tolerance, feature geometry, datum structure, part size, and reporting requirement.
Tight Tolerances Increase the Risk of Nonconformance
The smaller the allowable tolerance zone, the less manufacturing variation the design permits.
Material thickness variation, forming, springback, welding, hardware insertion, and finishing can all affect the final geometry of a fabricated sheet metal part.
For that reason, avoid applying unnecessarily tight tolerances across an entire drawing when only a few dimensions actually control the function of the assembly.
Questions to Ask Before Releasing the Drawing
- Is this tolerance required for fit, function, sealing, alignment, or another specific purpose?
- Does the GD&T control reflect an actual functional requirement?
- Are the datums clearly defined?
- Have critical-to-function dimensions been clearly identified?
- Does the inspection requirement match what the customer actually needs documented?
Prioritizing the dimensions and geometric controls that matter to the application can improve manufacturability while keeping the required inspection focused on the functional requirements of the design.
Provide a Fully Dimensioned Drawing for FAI
A 3D CAD model is extremely useful for manufacturing, but a formal inspection also needs clearly defined requirements against which the finished part can be evaluated.
Provide a fully dimensioned 2D drawing that identifies, as applicable:
- Drawing revision
- Material and material specification
- Dimensions and tolerances
- GD&T requirements
- Datums
- Hardware
- Finish requirements
- Critical characteristics
- Customer quality clauses
- Required inspection documentation
The drawing, CAD model, purchase order, and quality requirements should agree with one another before production begins.
When Is Another FAI Required?
A First Article Inspection isn't necessarily a one-time event for the entire life of a part.
Depending on the customer's requirements and the applicable quality standard, a complete or partial FAI may be required when a change could affect the part's fit, form, function, or manufacturing process.
Examples can include:
- Engineering or drawing revisions
- Changes to manufacturing processes
- Changes to tooling
- Changes to manufacturing location
- Changes that could affect fit, form, or function
- Production restarting after an extended interruption when required by the applicable standard or customer
If your organization has specific rules governing when an FAI must be repeated, include those quality requirements with the RFQ and purchase order.
AS9102 First Article Inspections
AS9102 is an aerospace standard for performing and documenting First Article Inspections.
If your project requires an AS9102 FAI, specify that requirement explicitly. Do not assume that a standard first-part inspection or dimensional inspection report will satisfy an AS9102 requirement.
Likewise, requesting an “FAI” does not automatically communicate that AS9102 documentation is required.
Identifying the requirement during quoting allows the fabricator to account for the required inspection, documentation, material traceability, and applicable process records from the beginning of the job.
For more information about FAIs, Certificates of Conformance, material certifications, and other quality documentation, see our guide to quality certifications and inspection reports for custom sheet metal parts.
First Article Inspections at Approved Sheet Metal
Approved Sheet Metal provides custom sheet metal fabrication and inspection services for prototype and low-volume production parts.
We manufacture parts for customers in demanding industries including:
ASM is ISO 9001:2015 certified and ITAR registered.
If your project requires an FAI, dimensional inspection report, material certifications, Certificate of Conformance, or other customer-specific quality documentation, include those requirements with your RFQ so they can be incorporated into the manufacturing and inspection plan.
Recommended Default Sheet Metal Tolerances
| DIM | Tolerance (MM) | Tolerance (Inches) | Description |
| A | ± 0.13 | ± 0.005 | Sheared Edge to Hole |
| B | ± 0.13 | ± 0.005 | 2 Holes on One Surface |
| C | ± 0.25 | ± 0.010 | Formed Edge to Hole |
| D* | ± 0.76 | ± 0.030 | Holes Across 2 Bends |
| E* | ± 0.76 | ± 0.030 | Holes Across 4 Bends |
| F | ± 0.25 | ± 0.010 | Sheared Edge to Bend |
| G | ± 0.38 | ± 0.015 | Across 2 Bends |
| H* | ± 0.76 | ± 0.030 | Formed Part |
Noted dimensions are to be taken while the part is in a restrained condition. Noted dimensions are for parts within a 12” envelope.
* Dimensions D, E and H are not recommended forms of dimensioning
These tolerances are recommended and best practices. We can obtain tighter tolerances (depending on part geometry/ construction), contact us for more information
