A cross section of welded material is polished and etched for examination.

The examination (macro or microscopic, the latter corresponding to magnifications higher than 10x), reveals the procedure and quality of the weld through internal discontinuities, weld profile, weld passes and sequence. Porosity, lack of weld penetration, lack of fusion, poor weld profile and other important defects can be checked in accordance with the relevant welding standard.

Equipment: microscopic optical material (magnification from 2x to 500x at welding lab)