The experimental section focuses on ways that fracture can be prevented. In order for fracture to be prevented, the way a material fractures must first be understood. Fracture can occur in a brittle or ductile manner. Once fracture behavior is grasped, then specific material properties, which predict when and what type of fracture occur, can be determined through a series of experiments. These properties are expressed in terms of fracture toughness, and the materials response to fatigue. Once these material properties are known, the engineer should be able to design in order to prevent fracture for a given application. The engineer's job is not only to predict and prevent fracture, it is also to ascertain the cause of fracture in already failed specimen. One of the engineer's key tools is in analyzing a fractured specimen is fractography, the study of fractured surfaces.