Radiography is one of the most useful of the non-destructive tests which can be applied for assessing the quality of the welded joints. Radiograph has been used for the inspection of welds of all types and thicknesses ranging from minute welds in electronic components to welds upto half metre thick employed in heavy fabrications.

Radiography can detect flaws or discontinuities in welds such as:
(i)Cracks.
(ii)Porosity and blow holes.
(iii)Slag, flux or oxide inclusions.
(iv)Lack of fusion between the weld metal and the parent metal.
(v) Incomplete penetration.