58 Cavities

Cavities are weld discontinuities consisting of rounded holes of various types, either within the weld or at the surface of the weld.

Cavities can be caused by either gas entrapment during solidification of the weld or contraction (or “suck back”) of the weld during solidification, which cannot be replaced by molten metal. Porosity and wormholes are cavity types formed by gases. Shrinkage voids are cavity type formed by contraction of the weld metal during solidification.

Please note: suck back is not a term used in welding, but it is a term used in industry. It is a “shop term”, so when you talk with welders they will know what you’re saying. Do not use that term with an inspector; the correct term is weld contraction.