Determining the mode of failure of a component may require analysis on a microscopic scale. A metallurgical analysis of the failed component will often include microscopic examination, material testing, and stress calculations. Examination of the failure site by scanning electron microscope will typically render information with respect to the nature of crack propagation, the granular structure of the metal, and the presence or absence of inclusions in the material. Physical testing of the fracture strength and surface hardness may also provide information as to how a component failed.