36 Soundness: Nick-Break Test

A nick-break test is a soundness test used to determine the internal quality of a weld. The objective of a nick-break test is to fracture a specimen through the weld so it can be examined for imperfections, such as porosity, inclusions, cracks, or incomplete fusion.

Once the specimen has been saw cut, it is then broken along the length of the weld and examined. If discontinuities are present, they are evaluated based on the acceptance criteria in the applicable code or standard. The nick-break test is specified by API 1104, Standard for Welding Pipelines and Related Facilities, to evaluate the quality of pipe welds.