Various macro- and microstructural changes are induced by an explosion and by the resulting shear stresses in metals exposed to it. At the microstructural level multiple slip bands or mechanical twins, induced by pressure and temperature waves caused by an explosion, can be observed. The occurrence of either depends on the type of metal, the pressure and the strain rate. Different situations regarding stainless steels, aluminium, copper and gold alloys are analysed. Calculations to evaluate which deformation mechanism is preferred for different fcc metals and alloys are reported. Results of field explosion experiments are incorporated into the evaluation of microstructural signs possibly induced on metal fragments by an unknown explosive event.