An impact test that can be made to provide preliminary visual inspection of the weld. Visual inspection of the broken section may reveal porosity, fracture mode, incomplete fusion, or any other defects which may be present.
A welder can use the nick-break test to check on a weld by making a test bar out of material similar to the metal being welded. If necessary, the test specimen may be cut directly out of the weld with a torch, and a new piece welded back in its place. As indicated in Figure N-3, the bar is nicked in the weld metal, 1/8 of its width on each side. It is preferable to make this nick or cut with a hacksaw, but if a hacksaw is not available, it can be made with a cutting torch.
A sharp blow with a hammer to the specimen held in a vise will break the weld metal from nick to nick. The hammer must be heavy and the blow sufficient to make a clean break. A visual inspection for defects can then be made.
The is used in welder performance testing to API 1104.