NADCAP (Special Process)

NADCAP accredits special-process suppliers through audited, procedure-driven controls to ensure consistent, traceable results for high-criticality aerospace and defense hardware.

Overview

NADCAP (National Aerospace and Defense Contractors Accreditation Program) is an industry-managed accreditation for “special processes” where final quality can’t be fully verified by inspection alone—heat treat, welding, NDT, chemical processing, coatings, composites, and more. Accreditation requires strict process control: qualified personnel, calibrated equipment, approved procedures, lot traceability, and periodic audits against aerospace checklists.

Choose NADCAP-accredited processing when your customer, drawing notes, or prime contractor flowdowns require it, or when part criticality makes process variation unacceptable (flight-safety, pressure, fatigue, fracture-critical). The tradeoffs are cost and lead time: tighter documentation, controlled parameters, mandatory records, and potential audit-driven constraints on scheduling or rework. It doesn’t replace engineering specs or good design; it reduces execution risk and improves repeatability across suppliers and lots.

Common Materials

  • Inconel 718
  • Ti-6Al-4V
  • Aluminum 7075
  • 17-4 PH stainless steel
  • A286
  • 4340 steel

Tolerances

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Applications

  • Heat treated landing gear components
  • Shot peened turbine disk features
  • Penetrant inspected engine brackets
  • Hard anodized aluminum housings
  • Plasma-sprayed wear surfaces on actuators
  • Bonded composite flight control skins

When to Choose NADCAP (Special Process)

Specify NADCAP when the process outcome drives safety or life and can’t be proven by dimensional inspection alone. It fits low-to-medium volume, high-criticality aerospace/defense hardware where traceability, controlled parameters, and audited execution are required. Expect higher quoting effort and longer lead times due to documentation and mandatory controls.

vs ISO 9001 (Quality Management)

Choose NADCAP when you need audited control of a specific special process (parameters, qualification, operator certification, equipment calibration, and records), not just a general quality management system. ISO 9001 can be sufficient for many commercial parts, but it typically won’t satisfy prime aerospace requirements for special-process accreditation.

vs AS9100 (Aerospace Quality)

Choose NADCAP when the requirement is tied to special-process execution—heat treat, NDT, coatings, welding—where checklist compliance and periodic technical audits are expected. AS9100 governs the overall aerospace QMS; NADCAP adds process-specific technical rigor and is often required by primes even when AS9100 is already in place.

vs ISO 13485 (Medical Device Quality)

Choose NADCAP when your supply chain is aerospace/defense and the controlled process itself is the risk driver (e.g., fatigue-critical heat treat or certified NDT). ISO 13485 focuses on medical device regulatory quality systems; it usually won’t meet aerospace customer flowdowns for accredited special processing.

vs IATF 16949 (Automotive Quality)

Choose NADCAP when customer requirements call for aerospace-style accreditation of special processes and audit checklists tied to technical parameters and lot traceability. IATF 16949 targets automotive APQP/PPAP and production controls; it doesn’t replace NADCAP where primes require accredited special processing.

vs ITAR Registered

Choose NADCAP when the key risk is process integrity and repeatability of special processing, not just export-control compliance. ITAR registration controls access and handling of defense articles; it doesn’t validate technical execution of heat treat, NDT, coatings, or welding.

Design Considerations

  • Call out the exact process spec and revision (e.g., AMS, ASTM, MIL) and clearly state NADCAP accreditation is required for that process family
  • Define acceptance criteria that drive the process plan (e.g., case depth, hardness range, coating thickness, NDT class/area, shot peen intensity/coverage)
  • Identify controlled/critical features and masking/keep-out zones on the drawing to prevent rework or scrap during chemical processing or coating
  • Plan for dimensional change from processing (growth, distortion, embrittlement relief bakes) and specify pre/post-process inspection datums and gaging method
  • Require full lot traceability and cert package content up front (C of C, process records, calibration references, operator qualifications) to avoid late documentation gaps
  • Avoid ambiguous notes like “heat treat per standard practice”; specify the condition, temper, and verification method to make quotes comparable