First Article Inspection Report Guide: Balloon Drawings, FAI Results and Production Approval

A first article inspection report, often called an FAI report, provides objective evidence that a supplier can manufacture a part to the released engineering requirements. It connects every drawing characteristic to a measured result, inspection method and pass/fail decision before routine production continues.

FAI is especially useful for custom CNC machined parts, sheet-metal components, die castings, molded parts, stamped parts and assemblies. These products depend on a specific combination of material, process, tooling, program, fixture, operator method and inspection plan. A visually acceptable sample is not enough when hidden dimensions, threads, coatings, material conditions or geometric tolerances control function.

An effective first article process is not simply “measure one part.” It begins with a controlled design package, identifies every requirement, verifies manufacturing records, inspects a representative sample, resolves nonconformities and records formal approval. This guide explains how to plan an FAI, create a balloon drawing, structure the report, select measurement methods and use the results for production approval.

Quick Answer: What Is a First Article Inspection Report?

A first article inspection report is a documented verification of a product made using the intended manufacturing process. The report normally includes:

• Part number, name and drawing revision.

• Purchase order or work-order reference.

• Supplier and manufacturing location.

• First article sample identification.

• Material, process and finish records.

• A ballooned drawing with numbered characteristics.

• Nominal values and drawing tolerances.

• Actual measured results.

• Inspection equipment or method.

• Pass/fail status and comments.

• Nonconformance and deviation references.

• Inspector, reviewer and approval signatures or electronic records.

The purpose is to confirm that the production definition has been understood and that the planned process can produce a conforming part. FAI does not by itself prove long-term process capability.

Why First Article Inspection Matters

Custom manufacturing contains many opportunities for interpretation error. A model may show the shape, but the drawing may control datums, tolerances, finish, material and special processes. The supplier may use the wrong revision, overlook a note, measure from the wrong datum or apply a general tolerance incorrectly.

FAI helps find these problems before a full batch is shipped. It can reveal:

• A missing or misread dimension.

• Incorrect material grade or temper.

• A wrong drawing revision.

• A feature programmed from an outdated CAD file.

• Datum interpretation differences.

• A tolerance that cannot be measured by the planned method.

• A coating that changes a critical fit.

• A thread with the wrong form, class or depth.

• An omitted deburring, marking or cleaning requirement.

• Tooling or fixture distortion.

• A special-process certificate that is incomplete.

• A packaging condition that damages finished surfaces.

Resolving these issues at the first article stage is usually faster and less expensive than sorting, reworking or replacing an entire lot.

First Article, Prototype and Production Sample: What Is the Difference?

These terms are often used interchangeably, but they answer different questions.

Prototype

A prototype verifies design intent, form, fit, function or appearance. It may use a different process, material or finish from production. Prototype inspection should match the prototype objective, and the results should not automatically approve a production process.

First-off part

A first-off part is the first unit from a setup, machine, cavity, tool or shift. It may be checked by the operator before the run continues. This is an important process control, but it is not necessarily a complete documented FAI.

First article

A first article is a representative unit produced using the intended process and evaluated against the complete released definition. It is accompanied by a controlled report and supporting records.

Pre-production or pilot sample

A pilot sample comes from a limited production-intent run used to verify tooling, sequence, yield, assembly and controls. The pilot may include an FAI plus capability, functional or reliability testing.

Golden sample

A golden sample is an approved physical reference, commonly used for appearance, color, texture, workmanship or assembly condition. It supports but does not replace dimensional and material requirements.

When Should an FAI Be Required?

An FAI is commonly requested when:

• A new part number is manufactured for the first time.

• A supplier or manufacturing site changes.

• Production resumes after a long interruption.

• A drawing or CAD revision changes fit, form or function.

• New tooling, fixtures, programs or major process routes are introduced.

• A tool is transferred, rebuilt or significantly repaired.

• A nonconformance suggests the process definition was misunderstood.

• The customer contract, industry standard or quality plan requires it.

• A new cavity, die, mold or production line is added.

Not every minor change needs a complete new FAI. A partial or delta FAI can verify only the affected characteristics when the unchanged baseline remains valid. The customer and supplier should agree on the scope before production.

Full FAI Versus Partial FAI

Full FAI

A full FAI re-verifies the complete part definition. It is appropriate for a new part, new supplier, major process change or missing/invalid baseline.

Partial FAI

A partial FAI covers changes from an approved baseline. The report should reference the previous FAI and identify why each repeated characteristic is included.

Examples of partial scope include:

• New dimensions introduced by a drawing revision.

• Features affected by a relocated datum.

• Coating thickness and final dimensions after a finish change.

• A feature produced by replacement tooling.

• Dimensions affected by a revised heat-treatment condition.

• Characteristics made at a transferred manufacturing operation.

A delta report should not assume that only the visibly edited dimensions are affected. Changes to material, datums, geometry or process sequence may influence several downstream features.

Define the FAI Requirement in the Purchase Order

Do not wait until parts are ready to request a detailed report. FAI affects quotation, schedule, inspection capacity and sample quantity.

The purchase order or quality clause should define:

• Applicable drawing and CAD revision.

• Full or partial FAI scope.

• Required report format or customer template.

• Number of samples to inspect.

• Whether every dimension or only selected characteristics is required.

• Special requirements for multi-cavity or multi-tool production.

• Required material and process certificates.

• Submission timing before shipment or production release.

• Customer review and approval responsibility.

• Handling of nonconforming characteristics.

• Record-retention period.

• Language, units and electronic file requirements.

If the customer requires a particular industry standard, form set or digital portal, provide access and instructions at the RFQ stage.

The Controlled Technical Package

The FAI is only as reliable as the definition used to create it.

The supplier should receive:

• Released 3D CAD file.

• Controlled 2D drawing.

• Part number, name and revision.

• Material specification and condition.

• Surface finish and special-process specifications.

• Referenced standards.

• Assembly or mating-part information when necessary.

• Customer quality clauses.

• Approved deviations or engineering changes.

• Inspection and packaging requirements.

CAD and drawing data must agree. If a conflict exists, production should stop for clarification. The supplier should not choose whichever value is easier to manufacture.

What Is a Balloon Drawing?

A balloon drawing is a controlled copy of the engineering drawing with a unique number assigned to every inspectable requirement. Each balloon number links to one row in the results report.

Ballooning creates traceability between source requirements and measured evidence. It also helps the reviewer confirm that nothing has been missed.

Characteristics commonly ballooned include:

• Linear and angular dimensions.

• Diameters and radii.

• Geometric tolerances.

• Datum feature identifications.

• Thread callouts.

• Hole quantity, size and depth.

• Surface roughness.

• Edge breaks and radii.

• Material and hardness.

• Coating, plating or paint requirements.

• Marking and serialization.

• Workmanship and visual notes.

• Cleaning and packaging notes.

• Referenced specification requirements when applicable.

The balloon drawing should use the same revision as the report and remain readable at the submitted page size.

How to Number Balloon Characteristics

Use a consistent method. Many teams number from the top left across the page, then continue downward. Others follow the normal drawing reading order or group dimensions by view.

Good practice includes:

• Assign one unique number to each distinct requirement.

• Keep numbering continuous across all drawing sheets.

• Do not reuse numbers after a drawing revision.

• Separate multiple requirements contained in one note when they need different evidence.

• Identify repeated or pattern features clearly.

• Link basic dimensions to the associated geometric tolerance when appropriate.

• Record reference dimensions as reference rather than pass/fail characteristics.

• Include specification-driven requirements that are not visible as dimensions.

Avoid balloons that cover dimension text, tolerance values or view details. If a crowded drawing becomes unreadable, use enlarged detail sheets while preserving traceability.

One Characteristic or Several?

A drawing callout can contain more than one requirement. For example, a threaded hole note may specify thread size, class, depth, quantity and positional tolerance. The report must make clear how each element was verified.

Possible approaches are:

• Give each requirement a separate characteristic number.

• Use one characteristic number with clearly separated result fields.

• Reference a dedicated thread or position report.

The chosen approach should let a reviewer determine the acceptance of every requirement without guessing.

FAI Report Structure

A practical FAI package can be organized into four sections.

1. Part and accountability information

This section identifies what was built and why the FAI was performed.

Typical fields include:

• Customer and supplier.

• Part number and description.

• Drawing and CAD revision.

• Purchase order and lot number.

• Manufacturing work order.

• FAI type: full or partial.

• Reason for the FAI.

• Sample serial number or traceability ID.

• Production quantity.

• Manufacturing location.

• Supplier approval.

2. Product and process accountability

This section records materials, special processes and functional tests.

Examples include:

• Raw-material certificate number.

• Heat, batch or lot number.

• Material grade, temper and condition.

• Heat-treatment certificate.

• Anodizing, plating, passivation or painting certificate.

• Welding, brazing or adhesive process record.

• Hardness or conductivity result.

• Leak, pressure or electrical test.

• Sub-tier supplier information.

• Certificate of conformity.

3. Characteristic results

This section links every balloon to the requirement and result.

Recommended columns include:

• Balloon number.

• Drawing sheet and zone.

• Requirement description.

• Nominal value.

• Lower and upper limits.

• Actual measured result.

• Unit of measurement.

• Inspection method or equipment ID.

• Sample or cavity ID.

• Pass/fail status.

• Comment or nonconformance reference.

4. Supporting evidence

The package may also contain:

• Ballooned drawing.

• Material and process certificates.

• CMM or optical reports.

• Surface-roughness traces.

• Thread-gauge results.

• Functional test records.

• Photographs of markings and cosmetic conditions.

• Approved deviation documents.

• Nonconformance and corrective-action records.

Record Actual Results, Not Only “Pass”

For variable characteristics, record the measured value whenever practical. A row that only says “pass” does not show margin to tolerance or allow future comparison.

Attribute results are appropriate for requirements such as:

• Correct marking present.

• Burrs removed.

• Packaging matches instruction.

• Go/no-go gauge accepted.

• Visual workmanship sample accepted.

Even for attribute checks, identify the gauge, standard or reference used. “Looks good” is not a controlled acceptance method.

Nominal Values and Tolerance Limits

The results table should show the actual acceptance limits rather than relying on the reviewer to calculate them.

Examples:

• For 25.00 ±0.05 mm, show 24.95 to 25.05 mm.

• For a one-sided limit, show the applicable maximum or minimum.

• For a limit dimension, copy the stated lower and upper values.

• For a geometric tolerance, identify the tolerance value, material condition and datum reference frame.

• For surface roughness, record the specified parameter and maximum value.

General tolerances must be applied correctly based on decimals, angle conventions, feature type and referenced standards. If the drawing does not define a tolerance for a required characteristic, request clarification rather than inventing one.

Units, Rounding and Measurement Resolution

The measurement system must have enough resolution for the tolerance. A display with the same increment as the full tolerance band does not provide useful confidence.

Establish rules for:

• Drawing units and report units.

• Conversion between inch and metric.

• Number of reported decimal places.

• Rounding method.

• Treatment of trailing zeros.

• Environmental compensation for precision measurements.

• Equipment accuracy and uncertainty.

Do not convert a value back and forth between units repeatedly. Use the drawing unit when possible and document any conversion.

Select the Right Inspection Method

Measurement method should match the feature, tolerance, geometry and surface condition.

No single instrument is best for every dimension. A detailed CMM report does not automatically verify thread form, roughness, hardness or coating adhesion.

Datum Setup and GD&T Results

Geometric tolerancing requires more than measuring coordinate values. The inspection setup must reproduce the specified datum reference frame and modifier conditions.

The FAI should make clear:

• Which physical features establish each datum.

• How datum targets are simulated.

• Whether the part is restrained or measured free-state.

• How maximum or least material modifiers are evaluated.

• Whether bonus tolerance is included.

• How composite position or profile is reported.

• Which software alignment is used.

A supplier-generated best-fit alignment can make a profile result appear better while ignoring the drawing datums. Best fit is useful for process analysis but should not replace the required acceptance alignment.

CMM Reports and Data Reduction

A coordinate measuring machine can inspect complex relationships efficiently, but the output should remain traceable to drawing characteristics.

Review:

• Program revision and CAD model revision.

• Probe type, qualification and access.

• Datum construction.

• Number and distribution of measured points.

• Filtering and fitting method.

• Temperature and stabilization.

• Whether measured points avoid burrs, radii or surface defects.

• Reported actuals versus calculated deviation.

Large raw CMM files can overwhelm the FAI package. Provide a clear summary keyed to balloon numbers, then retain the detailed output as supporting evidence.

Multiple Samples, Cavities and Tools

One sample may not represent every production source.

The plan should address:

• Multiple mold or die cavities.

• Duplicate stamping tools.

• Several CNC machines or fixtures.

• Family tools producing different part numbers.

• Left-hand and right-hand variants.

• Multiple production lines or sites.

• Additive builds with different plate positions.

If each cavity creates unique geometry, identify and verify each cavity. For a machined part using several identical fixtures, the customer may request one sample per fixture or a capability study on selected characteristics.

The report should never mix results from unidentified samples to create one apparently conforming part.

Material Verification

Dimensional conformance does not prove correct material.

Material evidence may include:

• Mill or resin certificate.

• Heat and lot traceability.

• Chemical composition.

• Mechanical properties.

• Temper or heat-treatment condition.

• Hardness.

• Positive material identification.

• Flammability, biocompatibility or regulatory documentation.

• Shelf-life and batch information for adhesives or coatings.

The purchase specification should state whether supplier certificates are sufficient or independent testing is required. A trade name without grade, standard and condition may be ambiguous.

Special Processes and External Suppliers

An FAI must include outsourced operations that affect the final definition. Examples include anodizing, plating, painting, passivation, heat treatment, welding, sterilization and nondestructive testing.

Verify:

• Approved process specification and revision.

• Sub-tier supplier identity.

• Certificate number and lot connection.

• Process type, class, color or thickness.

• Required tests and actual results.

• Masking and contact areas.

• Final dimensions after processing.

A certificate that merely says “processed as requested” may not demonstrate compliance with a detailed drawing note.

Surface Finish and Cosmetic Requirements

Appearance requirements need defined evidence. Use:

• Approved physical samples.

• Color standards or instrument values.

• Gloss range.

• Surface roughness.

• Texture reference.

• Controlled viewing distance, angle and lighting.

• Defect size and quantity limits.

• Marked Class A, B and hidden surfaces.

Photographs are helpful for documentation but may not reproduce color, gloss or fine texture accurately. Keep a controlled physical sample when appearance is commercially important.

Functional and Assembly Verification

Some requirements cannot be confirmed by dimensional inspection alone.

The FAI plan may include:

• Fit with mating components.

• Torque or pull-out tests.

• Leak or pressure testing.

• Electrical continuity and insulation.

• Motion, travel or actuation force.

• Seal compression.

• Fastener engagement.

• Adhesive cure and bond checks.

• Software or firmware configuration for mechatronic assemblies.

Document the test method, fixture, acceptance limit, actual result and sample condition. If a functional test is destructive, plan additional samples.

Inspection Before and After Finishing

Finishing changes dimensions and can hide or create defects. Decide when each characteristic is measured.

Examples:

• Threads may need gauge checks before and after plating.

• Critical bores may be machined after anodizing or protected by masking.

• Powder coating adds thickness to fits and slots.

• Heat treatment may distort flatness and position.

• Polishing can round edges and alter surface profile.

• Tumbling can change small features and break edges.

The FAI should represent the delivered condition. In-process measurements can support process control but do not replace final verification unless the characteristic becomes inaccessible and the plan explicitly permits it.

Handling Nonconforming FAI Results

Do not mark an out-of-tolerance result as accepted without an approved disposition.

The normal workflow is:

1. Record the actual result.

2. Identify the affected sample and characteristic.

3. Stop or contain additional production as required.

4. Create a nonconformance record.

5. Investigate whether the issue is measurement, documentation or manufacturing related.

6. Submit a deviation request if the part may be usable.

7. Rework or remake the sample when required.

8. Reinspect the affected and related characteristics.

9. Update the FAI record with traceable approval.

Customer approval of one deviation does not automatically change the drawing or authorize future production. The scope and duration of the concession must be clear.

Common FAI Mistakes

Wrong revision

The supplier inspects a part made from an old model or balloons an obsolete drawing. Prevent this with controlled release, purchase-order revision and document checks at job start.

Missing drawing notes

The report includes dimensions but overlooks material, finish, marking, edge and packaging notes. Treat every requirement as a characteristic or supporting record.

Pass/fail without actuals

Variable dimensions are marked “OK,” making margin and trend impossible to review. Record actual data.

Results copied from nominal values

Repeated perfect nominal values are a warning sign. Measurement records should reflect real variation and equipment resolution.

Unidentified sample

The report cannot be tied to a physical unit, cavity, lot or work order. Use durable sample identification and traceable packaging.

Inappropriate measurement method

A caliper is used on a close-tolerance bore, or a CMM best fit replaces the drawing datum setup. Match equipment to the requirement.

Coating ignored

Dimensions pass before finish but fail in delivered condition. Define measurement stage and final acceptance.

Unapproved deviation

An out-of-tolerance value is marked acceptable based on an email or verbal conversation. Reference formal authorization.

FAI treated as capability evidence

One conforming part is used to claim a stable process. Use statistical studies and ongoing controls when capability matters.

FAI Does Not Replace Process Capability

FAI verifies a defined sample and production setup. It does not show how the process will behave across time, material lots, tool wear, operators or environmental conditions.

For critical production, combine FAI with:

• Process flow and control plan.

• Measurement system analysis.

• Capability studies.

• Defined sampling plan.

• Tool-life controls.

• Preventive maintenance.

• In-process checks.

• Final inspection and traceability.

• Change-control requirements.

An acceptable first article authorizes the next phase; it is not permission to stop controlling the process.

Reviewing the FAI Package

The customer reviewer should check more than whether every row says pass.

Review questions include:

• Are part number and revisions correct?

• Is the sample made by the intended process and location?

• Does every balloon map to one result?

• Are all drawing notes addressed?

• Are actual values within the calculated limits?

• Are measurement methods suitable?

• Do GD&T results use the correct datums?

• Are certificates connected to the inspected lot?

• Are all cavities, tools or sources covered?

• Are deviations formally approved?

• Do attachments match the report identifiers?

• Are inspector and supplier approvals complete?

• Is the report legible and internally consistent?

Approval should be recorded with date, reviewer and any conditions. If changes are required, issue a clear return list rather than informal comments spread across emails.

Digital FAI and File Management

Digital systems can improve traceability and reduce transcription errors.

Useful features include:

• Drawing-characteristic extraction.

• Linked balloon and results tables.

• Automatic tolerance calculation.

• Direct import from CMM software.

• Calibration database links.

• Electronic signatures.

• Revision comparison.

• Certificate and photo attachments.

• Workflow status and approval history.

Automation does not remove the need for engineering judgment. Optical character recognition can misread symbols, limits and notes, so the final characteristic list still requires review.

Use stable file names, such as part number, revision, FAI type and date. Protect approved reports from silent editing and retain the native measurement files when required.

Supplier FAI Readiness Checklist

• Confirm purchase-order and drawing revision.

• Verify CAD and drawing agreement.

• Identify full or partial FAI scope.

• Build a complete characteristic list.

• Create a readable balloon drawing.

• Plan sample identification and traceability.

• Verify material availability and certificates.

• Confirm special-process sources and documentation.

• Select suitable calibrated inspection equipment.

• Prepare datum fixtures and functional gauges.

• Define final-condition measurement timing.

• Inspect all required samples, cavities and tools.

• Record actual values and method IDs.

• Resolve nonconformities before submission.

• Cross-check every report row and attachment.

• Obtain internal quality approval.

• Protect and retain the completed record.

Customer FAI Request Checklist

• Provide released CAD and drawings.

• State the applicable revision on the purchase order.

• Define the FAI standard or template.

• Specify full or partial scope.

• State sample quantity and cavity coverage.

• Identify critical and key characteristics.

• Provide special-process and material specifications.

• Define functional and cosmetic acceptance criteria.

• State required certificates and traceability.

• Define submission timing and production hold point.

• Identify who can approve deviations.

• Define record-retention requirements.

• Provide mating parts or gauges when needed.

• Confirm the review and approval workflow.

RFQ Checklist for Parts Requiring FAI

Include the following in the request for quotation:

1. Part number, name and revision.

2. 3D CAD and controlled 2D drawing.

3. Prototype and production quantities.

4. Manufacturing process and material specification.

5. All finishing and special-process requirements.

6. Full or partial FAI requirement.

7. Customer report template or applicable standard.

8. Number of FAI samples and cavity/tool coverage.

9. Critical characteristics and capability expectations.

10. Functional, leak, pressure or assembly testing.

11. Material and process certification requirements.

12. Required measurement methods or report formats.

13. Sample identification and traceability rules.

14. Production hold point pending FAI approval.

15. Delivery destination and target schedule.

Ask the supplier to quote FAI separately when useful. This shows the cost of ballooning, programming, inspection, certificates and review rather than hiding quality work in the part price.

Questions to Ask a Manufacturing Supplier

• Who prepares and independently reviews the balloon drawing?

• Can the supplier use the customer's required FAI format?

• Which characteristics will be measured by CMM, gauges or manual tools?

• How are calibration and measurement traceability controlled?

• How are drawing revisions prevented from mixing on the shop floor?

• Can every material and special-process certificate be tied to the lot?

• How are multi-cavity or multi-fixture results identified?

• What happens when a first article result is out of tolerance?

• Can raw CMM data and photos be provided when needed?

• How long are FAI records retained?

• How are partial FAI requirements evaluated after a change?

• Does production remain on hold until customer approval?

Frequently Asked Questions

How many parts are needed for first article inspection?

One part may be enough for a simple single-source process, but the requirement depends on risk, cavities, tools, fixtures and customer rules. Additional parts are needed for destructive tests or process studies.

Does every dimension need to be included?

A full FAI normally accounts for every drawing and specification requirement. Some commercial projects use a reduced dimensional report focused on critical features, but that should be agreed before quotation and should not be called a complete FAI if requirements are omitted.

Can the supplier use a prototype as the first article?

Only if the prototype was produced with the intended production process, material, tooling and controls. A CNC prototype cannot automatically approve an injection-molded or die-cast production process.

What is the difference between an FAI report and a dimensional inspection report?

A dimensional report records measured dimensions. A complete FAI also verifies part identity, revision, material, special processes, drawing notes, functional tests and supporting certificates.

Is a CMM report enough for FAI?

Usually not. CMM data may verify many geometric characteristics, but it does not by itself confirm material, finish, threads, roughness, hardness, markings, workmanship or packaging.

What happens after the FAI is approved?

The supplier may proceed according to the purchase order and quality plan. Ongoing production still requires in-process control, sampling, final inspection and change control.

When is a partial FAI acceptable?

A partial FAI is appropriate when an approved baseline exists and a controlled change affects a limited set of requirements. The customer should approve the scope and the report should reference the baseline.

Should actual measurement values be recorded?

Yes for variable characteristics whenever practical. Actual values show tolerance margin and support trend analysis. Attribute requirements can use pass/fail with a defined method or reference.

Can an out-of-tolerance first article be approved?

It may be accepted under a formal deviation if the customer determines the condition is usable. The report must show the actual result and reference the approval. The deviation does not permanently change the drawing.

Who approves the FAI?

The supplier normally approves the report internally, and the customer reviews it when contractually required. The purchase order should name the responsible approval authority and production hold point.

How long should FAI records be retained?

Retention depends on the contract, industry and product risk. Define a period in the quality requirements. Critical programs may require retention for the product life plus an additional period.

Does FAI prove that production is capable?

No. It proves that the inspected sample and supporting records met the defined requirements. Capability requires data from an appropriate series of production parts and a suitable measurement system.

Request Custom Parts With Documented Inspection

A well-planned first article process reduces approval risk because the supplier, drawing, manufacturing route and inspection evidence all refer to the same controlled definition. The result is faster review, clearer communication and fewer surprises during production.

Aluprototype supports custom CNC machining and manufacturing services, including dimensional inspection, material documentation, surface finishing and production support. For preparing a complete machining inquiry, use the CNC Machining RFQ Checklist.

Send the 3D CAD, 2D drawing, quantity, material, finish, FAI template, sample requirement and certificate needs through the request-a-quote page. The engineering and quality teams can review manufacturability, inspection scope and documentation before production begins.