First Article Inspection: What It Is and When to Require It

First article inspection (FAI) is one of the most effective tools available to buyers of precision machined components — and one of the most inconsistently applied. Some customers require it for every new part number. Others never ask for it and discover dimensional problems only after receiving a production shipment. Understanding what FAI entails, what it verifies, and when it’s genuinely necessary helps buyers protect their supply chain without over-specifying requirements that add cost without adding value.

FM Machine’s machined parts inspection capabilities include full first article inspection packages for customers who require formal documentation before production release.

What First Article Inspection Is

First article inspection is a formal verification process applied to the first part — or first representative sample — produced from a new setup, new tooling, or new production process. The purpose is to confirm that the manufacturing process is capable of producing parts that conform to all drawing requirements before production quantities are committed.

FAI is not the same as receiving inspection. Receiving inspection checks parts after they arrive. FAI is performed at the shop, before production release, to establish that the process is capable and controlled.

What a First Article Inspection Package Includes

The scope of FAI documentation varies by industry and customer requirement, but a complete FAI package typically includes:

• Balloon drawing: The part drawing with each measured dimension numbered (ballooned) to correspond to the inspection results
• Dimensional results: Actual measured values for every ballooned dimension, typically from CMM inspection, with nominal, tolerance, actual, and pass/fail for each
• Material certification: Certified material test report (MTR) confirming alloy, heat number, and mechanical properties
• Surface finish data: Profilometry results for surfaces with finish callouts
• Special process certifications: Documentation for any heat treatment, plating, anodize, or other special process applied to the part
• Certificate of conformance: A signed statement from the supplier confirming the part was produced to the drawing and specification

For aerospace applications, AS9102 defines the specific content and format requirements for first article inspection reports. Customers with AS9100D or AS9120D requirements typically reference AS9102 in their purchase order quality clauses.

When FAI Is Appropriate

First article inspection is warranted when the cost of a dimensional nonconformance in production exceeds the cost of the FAI itself. That threshold varies by application, but FAI is consistently appropriate for:

• New part numbers: The first time a part is machined, FAI confirms the process produces conforming parts before production quantities are run
• Drawing revisions: When a drawing is revised with dimensional changes, FAI on the revised part confirms the changes were implemented correctly
• Supplier changes: When a part moves to a new machine shop, FAI at the new supplier confirms their process capability before depending on them for production supply
• Process changes: New tooling, new CNC program, new fixture, or new material lot can all warrant re-inspection of a first article
• Long production gaps: If a part hasn’t been run in an extended period — programs may have been lost, tooling may have changed — FAI reestablishes process validity

When FAI May Not Be Necessary

FAI adds cost and lead time. For lower-risk situations, full FAI may be replaced by simpler verification:

• Repeat orders of established parts with no drawing changes and no supplier changes may require only in-process inspection and a certificate of conformance
• Parts with generous tolerances produced on well-established processes may be adequately controlled through statistical sampling rather than 100% first article documentation
• Prototype components where the drawing will change before production may not warrant full AS9102 FAI — though dimensional inspection of the prototype is still valuable design feedback

The decision should be based on risk — the criticality of the application, the consequences of a nonconformance, and the maturity of the production process.

How to Specify FAI Requirements

FAI requirements should be included in the purchase order and on the drawing notes, not communicated verbally or assumed. Specify:

• Whether FAI is required (yes or no)
• The applicable standard (AS9102 for aerospace, or customer-specific format)
• Which dimensions are to be fully documented versus sampled
• Whether material certifications and special process certs are required
• Disposition — whether you require FAI approval before production shipment is released

Requirements that are specified in the purchase order are priced into the quote. Requirements communicated after the fact delay shipment and create cost disputes.

Using FAI Data to Improve Your Supply Chain

FAI documentation is more than a compliance exercise. The dimensional data in an FAI package reveals how the production process is centered within the tolerance band — which features are comfortably in tolerance and which are close to the edge. Features that measure consistently near one tolerance limit across multiple first articles indicate a process that may be drifting or inadequately controlled. That information is worth having before production quantities are in the pipeline.

FM Machine produces CMM-based FAI packages that give customers the dimensional data to make informed decisions about production release. Our achieving tight tolerances guide covers the process controls that make FAI results meaningful rather than one-time snapshots.

Require FAI on Parts That Matter

First article inspection is a production release gate, not a paperwork exercise. Applied to the right parts at the right points in the supply chain, it prevents dimensional problems from reaching your assembly floor.

Request a quote from FM Machine and specify your FAI requirements in the RFQ — we’ll scope it correctly from the start.