The lateral stress in a titanium aluminide alloy has been investigated under different impact conditions during shock loading, using embedded manganin stress gauges. From this, the variation of the materials shear strength with longitudinal stress has been determined. Results show that shear strength increases rapidly with increasing impact stress, as would be expected in a material that displays a high degree of work hardening. The results from this alloy have also been compared to those of a similar material, which was tested in a different microstructural state. Significant differences were noted and explained in terms of the variation in phase distribution and grain size. (C) 2001 American Institute of Physics.