Abstract: The control specimen according to the invention consists of a metal basic body and artificial inclusions arranged in it, where the inclusions are suitably sintered, non-metallic configurations arranged according to size and distribution conforming to the purpose of the test. During production of the control specimens at least one layer is formed with metal melt, into which inclusion, inclusions is/are inserted conforming to the shape and arrangement of the required fault location or locations. It is practicable to form at least one further upper layer from the metal melt inclusions. Further inclusions may be arranged in the top layer and in given case further top layers are formed with or without inclusions. The artificial defects can be produced either by forming cavities into the layer after solidification and cooling, and inserting the inclusion(s) into the appropriate cavity or cavities, or spreading them into the layer-forming metal melt before solidification.