Who can inspect a steel weld with NDT (UT, MT, PT or RT)?
Weld NDT is chosen by joint type, defect type and code: UT and RT find internal discontinuities, MT and PT find surface-breaking ones. Acceptance criteria come from the governing code, such as AWS D1.1 for many structural steel projects.
What the method covers
Field or shop welds on structural steel; technicians are typically certified under an employer programme such as ASNT SNT-TC-1A.
Applicability caveats
- MT works only on ferromagnetic materials; PT needs clean, accessible surfaces.
- NDT detects indications — rejection depends on the code and engineer.
- Destructive weld tests (macro-etch, bend, tensile) are separate lab work.