Buyers qualifying an aerospace or defence machining supplier meet both standards on day one. Here is what ISO 9001 and AS9100 each cover, how they differ, and which one you actually need from a subcontractor.
What is ISO 9001?
ISO 9001 is the international standard for a quality management system (QMS) — the way an organisation controls its processes to deliver consistent, conforming products. It is industry-agnostic, used by manufacturers, service firms and every sector in between. Certification is granted by an accredited body after audit; Milltech's ISO 9001:2015 system is approved by LRQA (approval no. ISO 9001–0006386, first approved 2009), covering precision and contract CNC machining and associated assembly.
What is AS9100?
AS9100 is the aerospace, space and defence quality standard. It contains the full text of ISO 9001 and layers on requirements those sectors demand — risk management, configuration management, first-article inspection, counterfeit-part prevention, product safety and tighter traceability. It is the benchmark primes use to qualify suppliers for flight-critical and defence work.
How do ISO 9001 and AS9100 differ?
They are not competing standards — AS9100 is a superset of ISO 9001:
- Scope: ISO 9001 is general; AS9100 is aerospace/defence-specific.
- Extra controls: AS9100 adds configuration and risk management, first-article inspection, counterfeit-part prevention and product-safety requirements.
- Traceability: AS9100 mandates stricter, documented material and process traceability.
An AS9100 supplier necessarily meets ISO 9001; an ISO 9001 supplier does not automatically meet AS9100.
Which does your machining supplier need?
It depends on your sector. For general, energy, medical and industrial work, ISO 9001 is the expected baseline. For flight-critical aerospace and defence programmes, buyers typically require AS9100 and often JOSCAR registration on top. Milltech holds ISO 9001:2015 and is JOSCAR registered and Cyber Essentials Plus certified, and applies aerospace-grade documentation and traceability to defence work. Send your requirements and we will confirm exactly what applies to your parts.
