AMS 2644: Inspection, Liquid Penetrant
Aerospace standard for liquid penetrant testing methods and procedures for aerospace materials and components.
SAE International maintains AMS 2644 as a published consensus standard used across the NDT industry.
AMS 2644 becomes enforceable when invoked by a contract, regulatory citation, or another standard that references it as the controlling document.
AMS 2644 is invoked when the scope of work matches its title — inspection, liquid penetrant — and when the contract or regulatory regime cites it as the controlling document. Aerospace work treats the standard as a floor rather than a ceiling — most prime contractors layer their own internal procedures on top, with tighter acceptance criteria than the published code.
Methods covered
Industries
- Aerospace
- Defense
- Personnel qualification: examinations under AMS 2644 must be performed by inspectors qualified and certified to a recognised scheme (typically ASNT SNT-TC-1A, CP-189, or ISO 9712 depending on jurisdiction), with documented training hours, vision tests, and a controlling written practice.
- Written procedure: every examination requires a written, controlled procedure that names the method, equipment, calibration steps, scanning pattern, and acceptance criteria — and is qualified before first use.
- Penetrant process control: penetrant family (visible / fluorescent), sensitivity level, dwell times, removal method (solvent / lipophilic / hydrophilic), and developer type are all controlled and documented for each examination.
- Acceptance criteria: indications are evaluated against the standard's tabulated limits (length, depth, alignment, frequency); any indication exceeding the criteria is recorded, dispositioned, and either repaired or evaluated for fitness-for-service.
- Documentation: examination reports must include enough information for a third party to reproduce the inspection — equipment serial numbers, calibration records, inspector ID, sketches of indications, and the controlling procedure revision.
AMS 2644 is maintained on its publishing organisation's revision cycle. The version cited in any contract or written inspection program should be tracked so that revisions can be reviewed against the existing inspection plan and any clause changes worked into the next procedure update.
An aerospace manufacturing line will reference AMS 2644 on the inspection-traveler card for each component; the inspection is performed by NAS 410-qualified personnel, and any indication exceeding the standard's limits triggers a Material Review Board disposition before the part is released to assembly.
What does AMS 2644 cover?
AMS 2644 (Inspection, Liquid Penetrant) is published by SAE International. Aerospace standard for liquid penetrant testing methods and procedures for aerospace materials and components..
Is AMS 2644 mandatory or voluntary?
AMS 2644 is a consensus standard. It becomes mandatory when invoked by a contract, by another code that cites it (for example ASME Section V calling out an ASTM practice), or by a regulator that has adopted it into law in a specific jurisdiction.
Who is qualified to perform inspections under AMS 2644?
Inspections under AMS 2644 must be performed by personnel qualified and certified to a recognised NDT certification scheme — most commonly ASNT SNT-TC-1A or CP-189 in the United States, ISO 9712 in much of the rest of the world, and NAS 410 for aerospace work. The written practice that controls qualification must be in place before any examination is started.
Which other standards are commonly cited alongside AMS 2644?
AMS 2644 is most often cited together with the parent code that brings it into the contract — typically ASME Section V or VIII for U.S. pressure equipment, AWS D1.1 for structural welding, API 510/570/653 for in-service petroleum equipment, or the matching EN/ISO standard for European and international work.
Standard Code
AMS 2644
Organization
SAE International
Methods Covered
1 method(s)
Industries
2 sector(s)
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