Aerospace CNC Requirements: A Buyer's Checklist

LightsOut CNC Journal · 7 min read

Sourcing a machined part for an aerospace or defense program carries a different kind of risk than sourcing most other manufactured goods. A nonconforming bracket on a consumer product is a return. A nonconforming bracket on a flight program can mean a grounded aircraft, a failed audit, or a program-level supply chain finding. That's why qualifying a new machine shop for this kind of work involves a longer checklist than "can you hold the tolerance." Here's what that checklist actually covers, and where we stand against it today.

1. Material traceability and certification

Every piece of raw material used on an aerospace part needs a paper trail back to its source — mill certifications, material certs, and lot traceability that ties a specific bar or plate of stock to the specific parts machined from it. A shop should be able to tell you, for any part it ships, exactly which material lot it came from. We machine primarily in aerospace-grade aluminum — high-strength 7075-T6 and MIC-6 cast tooling plate — and maintain material certification and lot traceability on every job.

2. Quality management system status

This is the item buyers should scrutinize most closely, because it's also the one most often misrepresented. AS9100D is the aerospace industry's quality management standard, built on top of ISO 9001. A shop's actual certification status — certified, audited-and-pending, or working toward it — should be stated plainly, not implied. We are direct about where we stand: our quality roadmap targets ISO 9001:2015 as the foundational baseline, AS9100D as the aerospace-specific standard we are working toward, ISO 13485 as a year-two target for medical-device-adjacent work, and NADCAP special-process accreditation further out for the primes that require it. None of these are complete yet, and we say so on our Quality & Compliance page rather than only in the fine print.

3. Export control and ITAR handling

If a part or its technical data is subject to ITAR or EAR export control, the shop handling it needs a real process for controlled-access data handling — not just a statement that they're "familiar with ITAR." Ask directly whether a shop is registered with the U.S. Department of State's Directorate of Defense Trade Controls, and if not, what stage that registration is at. Our own registration is in progress, and until it is complete, customers submitting export-controlled drawings or models are responsible for ensuring proper authorization and marking, consistent with the terms we post publicly.

4. In-process inspection and documentation

A part that's only inspected after it's finished is a part where a problem is caught too late to do anything but scrap it. Look for shops running in-process probing — verifying setups, datums, and critical features while the part is still in the machine — rather than relying solely on a final CMM check. Ask how First Article Inspection (FAI) reports are generated and what digital traceability exists connecting a specific serial or lot number back to its machining program, tooling, and inspection data.

5. Demonstrated tolerance and repeatability

Aerospace tolerances are rarely exotic on paper, but holding them consistently across a production run is where shops separate themselves. Ask for the tolerance capability a shop actually holds in production, not just the tightest tolerance their machine spec sheet claims is theoretically possible. Our production tolerance capability is ±0.0005", held across 5-axis single-setup work on our Matsuura MX-330 centers.

6. Delivery predictability and capacity

A supplier with a great quality system but unpredictable lead times is still a supply chain risk. Ask how a shop's quoted lead time is generated — is it a real capacity check against current shop load, or a rule-of-thumb estimate padded to cover uncertainty? Because our machining capacity isn't bottlenecked by single-shift scheduling, our quotes are priced against actual available machine time — not padded to cover a schedule nobody has visibility into.

The short version

• Material certs and lot traceability on every part, not just on request.
• An honest, specific answer on AS9100D / ISO / NADCAP status — certified, in progress, or not started.
• A real ITAR/export-control process, with registration status stated plainly.
• In-process probing and FAI documentation, not just a final inspection report.
• A stated, demonstrated tolerance capability — not a marketing number.
• Lead times based on actual shop capacity, not padded guesswork.

A shop that can answer all six of these directly, in writing, is one worth qualifying. If any answer is vague, that vagueness is itself useful information about the risk you're taking on.