AS9100 and what it actually tells you about a supplier

“AS9100 certified” appears in almost every capability deck aimed at aerospace buyers, and it gets treated as a single yes/no gate: certified shops are in, everyone else is out. That shortcut is convenient and it is also frequently wrong, in both directions.

What AS9100 actually is

AS9100 is a quality management system standard built on top of ISO 9001, with aerospace-specific requirements added — configuration management, first article inspection, key characteristic control, counterfeit parts prevention, and traceability through the supply chain. A shop earns it through an audit by an accredited certification body, repeated on a cycle, and the registration is checked against a public database (the OASIS registry).

That audit tests whether the shop’s system does what it says it does — that nonconformances get recorded, that corrective actions get closed, that documents are controlled. It does not directly test whether the shop is good at cutting titanium.

What it proves

A genuine, current AS9100 registration proves the shop has a functioning quality management system that has passed an independent audit, and that it carries the administrative overhead of configuration control, document control and formal corrective action. For a program that specifically requires it — many aerospace primes do, contractually — there is no substitute, and no argument to be had. If the specification requires it, the shop needs it.

What it does not prove

It does not prove the shop has ever machined your specific alloy. It does not prove the specific manufacturing cell, tooling or operator working on your job is good — a certificate covers the facility’s system, not any one process. And it does not prove the price is fair: certified shops carry the audit and documentation overhead on every job, whether your part needs that overhead or not, which is one of the five reasons the same drawing comes back at three different prices.

Certification status is also easy to misstate, deliberately or not. “AS9100 compliant” is not the same claim as “AS9100 certified” — compliant can mean “we follow similar practices” with no audit behind it at all. The only way to know which one you are getting is to check.

How to actually check it

Ask for the certificate number and the certifying body, then verify it in the IAQG OASIS database rather than trusting the PDF on the wall in a photo. A genuinely certified shop hands this over instantly, because checking it costs them nothing. Hesitation is itself information.

Confirm the scope. A registration can be scoped to specific processes, locations or product families — a shop certified for sheet metal fabrication is not certified for five-axis titanium machining just because both happen under the same roof.

What to ask when your requirement is not contractually AS9100

Most parts do not actually require it — the specification requires specific outputs (first article inspection, material traceability, key characteristic control), and a non-certified shop that runs a disciplined process can deliver all of them without carrying the certificate’s administrative overhead into your price. In that case, ask for the outputs directly:

• Does the shop run first article inspection on new parts, whether or not it is called AS9102?
• Can the finished part be traced back to its material heat lot? See material certificates and traceability for what that actually requires.
• Are key characteristics identified and controlled, or is everything inspected — or nothing?

A shop that answers those three specifically, without reaching for the certificate as a substitute answer, is telling you more than the certificate would.

Where we stand on this

We are a trading company, not a certified facility, and we do not claim otherwise. What we check, before placing an order with any shop in our network, is exactly this list: registration status verified against the public registry when a shop claims it, and the underlying outputs checked directly when it does not, against the criteria published in the shop audit standard. Where a certificate fits among the other checks on a supplier is set out in our guide to choosing an exotic alloy machining supplier.

Tell us what your specification actually requires and the quote places the part against those requirements, not against a logo on a slide.

For the rest of the acronyms that show up on a quote — CoC, MTR, FAI and the EN 10204 sub-types — see the glossary.