Nick Break Fracture Test
The Nick Break Test or Fracture is used to determine the quality of a weld, and involves breaking open the weld length-wise, and then visually inspecting the exposed weld interior for any internal imperfections such as lack of sidewall fusion, lack of inter-run fusion and porosity. The test can be carried out for both Butt Welds and Fillet Welds Test coupons. For Butt Welds, a groove is machined along the weld centre line to provide a convenient fracture path before the specimen split open via a hydraulic press or a conventional hammer.
For Fillet Welds, use of a hydraulic press to apply sufficient force to the opposite side of the weld fillet is typically sufficient to fracture the weld for inspection. The test is often requested when inspection of the entire weld length is required, as opposed to inspecting only a cross sectional area of the welded specimen. The test typically forms part of a suite of tests used to evaluate a welder’s skills for Welder Qualification.