Room‐temperature tensile deformation experiments were performed on aluminum, magnesium, and molybdenum at 10−10Torr; at the same time, chamber pressure and residual gas species were monitored. Pressure increases noted during the deformations were attributed to specimen desorption resulting from imposed stresses and their concomitant lattice distortions. Hydrogen and methane were evolved from all three metals. The extent of desorption, however, was different for each material.