Charpy impact specimens, one third the size of standard specimens in all dimensions have been tested for a variety of steels and the data have been compared to standard specimen data. The absorbed energy curves are qualitatively similar for both specimen types, and quantitative evaluations of dynamic yield strength and cleavage fracture stress are similar as well. However, differences in constraint between standard and subsized specimens must be accounted for, and these differences are influenced by the flow behavior of the test material.