34 Soundness: Macro-Etch Test

A macro-etch test is a test in which a specimen is prepared with a fine finish, etched, and examined using no magnification or low magnification.

After surface preparation, the specimen is cleaned with a suitable solvent to remove grease, oil, and other residues that may interfere with etching. Once the surface has been cleaned, it is etched with an appropriate etchant and examined.

The fillet weld break test with macro-etch is used for the qualification of welders and welding operators in accordance with AWS D1.1, Structural Welding Code—Steel. A slightly different version of the fillet weld break test is used to qualify tack welders.

Etching can only be used to detect surface defects, or any discontinuities right at the cut.