Fracture toughness coupons should conform to the latest requirements defined by ASTM E 399. Crack location with respect to weldment is of particular importance, and the criteria for validity of specimen must be met. Coupons used for evaluation of other weldment properties, such as fillet-weld shear strength and creep or stress rupture, also require definition in order to be used for design strengths.
Availability of accepted test methods for base metal evaluation, as evidence by federal and ASTM standards, has resulted in their general application to testing of weldments. These standards control test equipment, data accuracy, and loading rates. Reference to existing base metal test methods are generally considered satisfactory for mechanical property testing of weldments except for configuration definition. The testing practice and any deviations should be reported when data samples are generated. In no case may a test result be discarded on the basis of a defect found after final inspection—for example, during post-test examination of fractured surfaces.