<p>The mechanism of formation of volcanic bombs is not well-understood at present. Although several alternative models have been proposed, it is difficult to assess them due to the lack of quantitative indicators. Measurement of the anisotropy of magnetic susceptibility (AMS) of different bomb morphologies might provide an useful quantitative reference frame upon which such models can be mutually compared. In this work, we present the results of the measurement of the AMS of six different bomb morphologies. The results show that similar macroscopic morphological types can be achieved by more than one mechanism of deformation, but the internal structure of each bomb retains clues concerning the different mechanisms of deformation that acted upon it before its effective solidification. Bombs of small size may have experienced complex sequences of deformation that are superimposed in different layers of the bomb, but such complexity is not necessarily observed in bombs of larger size, as the latter do not necessarily experienced more complex sequences of deformation events. Furthermore, the breadcrust texture of a bomb may not reflect gas expansion that influenced the entire volume of the bomb, but can be related only with a superficial layer and the flattening of a bomb may be due to rotation effects around an axis, which may be defined by an embedded object. Although the diversity of AMS signals is large, it is considered that this tool provides valuable information that can help us to better understand the mechanism of formation of this type of pyroclastic products.</p>