First Article Inspection Injection Molding First Article Inspection is your proof that the tool makes what it’s supposed to make. I’ve seen FAI submissions rejected because of missing dimensions. I’ve seen projects delayed because the documentation wasn’t complete. Here’s how to get FAI right the first time.

Key Takeaways

| Aspect | Key Information |

Understanding FAI

What Is FAI? FAI verifies that the first production parts meet all drawing requirements before full production begins.

When FAI Is Required TriggerTypical RequirementNew toolAlways requiredTool modificationIf CTQs affectedNew supplierUsually requiredProcess changeIf quality affectedAnnual requalificationPer customer

FAI Scope ScopeDefinitionFull FAIAll characteristics (100+ dimensions)Partial FAIChanged has onlyPlus-1First production part

FAI Requirements by Standard

PPAP Requirements (AIAG) LevelDocumentationTypical Use1Part submission warrant onlyRare2Warrant + results for one partCommon3Warrant + results for all samplesMost common4Warrant + all dataCustomer specific5Warrant + all data + reviewedCritical parts

Key PPAP Elements ElementDescriptionRequired?PSWPart Submission WarrantYesIMDSMaterial declarationYesAppearance approvalAAI reportIf applicableDimensional resultsFull layout inspectionYesMaterial certsTest resultsYesMold/tooling recordTool historyYesProcess flowPFMEA referenceYesPFMEAProcess failure modesYesControl planQuality control planYesMSAMeasurement system analysisYesProcess capabilityCpk studyYes

Dimensional Inspection Requirements

Measurement Plan StepActionOutput1Review drawingIdentify all dimensions2Classify dimensionsCritical, major, minor3Select measurement methodsCMM, gages, etc.4Define locationsGD&T interpretation5Create inspection planDocument procedures

Dimension Classification ClassSymbolMeasurementAcceptanceCritical★100% measurementPer toleranceMajor,

Sampling or 100%Per toleranceMinor, SamplingPer tolerance

Critical Characteristics IdentificationMethodVerificationFit dimensionsCMM or functional gage100%Regulatory dimensionsCMM100%Safety dimensionsCMM100%Critical tolerancesCMM100%

Non-Critical Dimensions Verification MethodFrequencyNotesCMMSample (3-5 parts)Random selectionGo/No-goSampleAttribute checkVisualSampleDocument

Measurement System Requirements

MSA (Measurement System Analysis) AnalysisPurposeAcceptanceGage R&RRepeatability, reproducibility<10% acceptableBiasAccuracy<5% of toleranceLinearityAccuracy across range<10% of toleranceStabilityOver timeStatistical control

Gage R&R Acceptance Criteria Gage R&RInterpretationAction<10%AcceptableUse as-is10-30%MarginalMay be acceptable>30%UnacceptableImprove system

Measurement Equipment MethodUseUncertaintyCMMPrecision dimensions<0.0001”Optical comparatorProfiles, contours<0.0002”Height gage2D dimensions<0.0001”Functional gagesFit verificationBased on toleranceHand toolsGeneralPer tolerance

FAI Documentation

Part Submission Warrant (PSW) FieldInformationSupplier name____________Customer____________Part number____________Part name____________Supplier code____________Production plant____________Tool number____________Tool status[ ] Production [ ] ModifiedSupplier code____________Change level____________Issue date____________

Dimensional Results DimensionSpecActualPass/FailMethod1.001±0.0051.003PassCMM2.500±0.0102.498PassCMM3.050±0.0203.045PassGage……………

Material Certification TestMethodSpecResultPass/FailMelt flowASTM D123820-30 g/10min24.5PassTensileASTM D638>6000 psi6850PassIzod impactASTM D256>3 ft-lb/in4.2Pass

Process Capability Requirements

Capability Study Requirements FactorStandardNotesSample size≥30 consecutive partsProduction conditionsData collection1 shift minimumNormal productionAnalysisX-bar/R or I-MRBased on data typeReportingCpk, Ppk, PpAll indices

Capability Acceptance CharacteristicCpk RequirementCritical (★)≥1.67Major≥1.33Minor≥1.00

When Cpk Is Low ActionThresholdPurposeDocumentCpk < 1.33TraceabilityInvestigationCpk < 1.00Root causeContainmentCpk < 0.67Prevent shipmentRe-submissionAfter improvementVerify fix

Visual and Appearance Standards

Appearance Approval ElementRequirementSurface finishPer specColorMaster standardGate vestigePer standardParting linePer standardPackagingPer requirement

AAI (Appearance Inspection) ItemStandardEvaluationColorMaster sampleMatchGlossMaster sample±5 unitsSurfaceSpecificationNo defectsGateStandardAcceptable

Submission Requirements Checklist

Pre-Submission Tool completed and trials run Process validated Parts production-ready All dimensions identified Measurement system ready Documentation started

Documentation PSW completed and signed Dimensional results (full layout) Material certifications MSA reports Process flow diagram PFMEA Control plan Capability studies IMDS submission AAI report (if applicable) Tool drawings (as applicable)

Part Submission Sample parts (quantity per customer) Representative production parts All cavities represented Proper labeling Packaging per requirement Shipping documents

Common FAI Failures

Documentation Issues FailurePreventionMissing dimensionsComplete drawing reviewOutdated documentsVersion controlIncomplete recordsChecklist completionUnclear specificationsClarify before starting

Measurement Issues FailurePreventionWrong measurement methodDefine in inspection planInadequate MSAComplete before FAIPoor samplingStatistical sampling planWrong equipmentCalibrated, appropriate tools

Process Issues FailurePreventionNon-representative partsProduction conditionsProcess not capableCpk before FAITool not production-readyProper debuggingOperator not trainedTraining records

FAI Report Structure

Standard FAI Report

 SECTION 1: GENERAL INFORMATION
- Part number, name, revision
- Supplier name, location
- Tool number, status
- Date of FAI
- Customer requirements SECTION 2: PART SUBMISSION WARRANT
- Signed PSW form
- Approval signatures SECTION 3: DIMENSIONAL RESULTS
- Inspection plan
- Full layout results
- Acceptance status
- Non-conforming items SECTION 4: MATERIAL CERTIFICATION
- Resin certification
- Test results
- Compliance verification SECTION 5: PROCESS DOCUMENTATION
- Process flow
- PFMEA
- Control plan SECTION 6: MEASUREMENT SYSTEM
- MSA reports
- Equipment calibration SECTION 7: PROCESS CAPABILITY
- Study data
- Cpk/Ppk results
- Analysis SECTION 8: VISUAL/APPEARANCE
- AAI report
- Master samples
- Standards SECTION 9: TOOLING
- Tool drawings
- Maintenance records SECTION 10: APPROVALS
- Quality approval
- Engineering approval
- Customer approval

The Bottom Line FAI is your quality promise—the documentation that says “we made it right, we measured it right, and it meets requirements.” Complete the documentation. Use the right measurement systems. Verify the capability. Don’t submit incomplete FAI. Don’t use uncalibrated equipment. Don’t skip the process validation. That’s how you get FAI approved the first time.