AS9100 vs ISO 9001: which one your part actually needs

505 shops hold AS9100 and 815 hold ISO 9001. The difference decides whether your part can fly.

The two standards are not tiers of the same thing

ISO 9001 says a company has a quality management system and follows it. AS9100 says the same, plus roughly a hundred additional requirements written for parts that go on aircraft: configuration management, counterfeit-part prevention, first-article inspection, risk management, and traceability that survives an audit years after delivery.

AS9100 contains ISO 9001 entirely. A shop holding AS9100 meets ISO 9001 by definition. The reverse is not true, and specifying the wrong one is the most common way a buyer either pays for compliance they do not need or discovers too late that their supplier cannot support the program.

What the numbers look like across the three states we cover

Of the shops in this directory, 815 state ISO 9001 and 505 state AS9100.

	AS9100	ISO 9001
California	341	424
Ohio	82	222
Texas	82	169

The Ohio ratio is the interesting one. Ohio has 222 ISO 9001 shops and 82 with AS9100 — roughly one in three. California runs closer to four in five. If you are sourcing an aerospace part in the Midwest, the pool is narrower than the headline shop count suggests, and that is worth knowing before you build a bidder list rather than after.

“Compliant” is not “certified”, and the distinction is load-bearing

You will see suppliers describe themselves as “AS9100 compliant.” That phrase means the company believes it follows the standard. It does not mean a registrar audited them and issued a certificate, and it carries no expiry date because there is nothing to expire.

Certification is a third party putting their name on it, on a schedule, with surveillance audits in between. When a shop is certified, there is a certificate with a number and a date on it. Ask for it. A supplier who is certified will send it in a minute; a supplier who is “compliant” will explain.

This directory records the distinction rather than flattening it: where a shop publishes an actual certificate, the listing says so and shows the expiry.

When ISO 9001 is genuinely the right answer

Specifying AS9100 when the part does not need it shrinks your bidder pool — in this directory 505 shops state AS9100 against 815 for ISO 9001 — and raises your price, because the shop is carrying real audit cost and prices accordingly.

ISO 9001 is the right specification for industrial, commercial and most automotive work, for prototypes and fixtures, and for anything where the failure mode is inconvenience rather than an airframe. Reach for AS9100 when the part flies, when your customer's contract flows the requirement down to you, or when you will need traceability years from now.

What to ask for, in order

The certificate itself — number, registrar, expiry.
The scope statement on it. A certificate can cover one facility or one process; a multi-plant supplier may be certified at a site that is not the site making your part.
Whether ITAR registration is also needed. 312 shops in this directory state ITAR registration, well under the AS9100 population — defence work frequently needs both, and they are separate things.

Shops that state AS9100 in California, Ohio and Texas

A specialist calls you within one business day. No account, no price guessing.

Counted from the shops on record at the last build. Every capability, certification and machine below comes from the shop’s own published information or a public federal record, and each one links to the page that carries its source sentence. Figures recomputed 2026-10-03.

The two standards are not tiers of the same thing

What the numbers look like across the three states we cover

“Compliant” is not “certified”, and the distinction is load-bearing

When ISO 9001 is genuinely the right answer

What to ask for, in order

Shops that state AS9100 in California, Ohio and Texas

California — 341 shops

Ohio — 82 shops

Texas — 82 shops

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