We propose to exploit the high resolution and well defined peak shape on HRPD to measure the evolution of peak profile shape at the early stages of deformation in stainless steel (304H) and an aerospace grade titanium alloy (Ti-6Al-4V). Traditionally, diffraction peak shape studies focus on heavily deformed materials. In this experiment, we propose to study the early stages of deformation (strain <10%), which is relevant to engineering applications. The aim is to compare the change in peak broadening anisotropy (in reciprocal space) with direction with polycrystal deformation modelling predictions. This will contribute to the development of these models, which will form the base of future, microstructure based models that engineers will use to design new more metal components and to monitor their performance.