Modeling of the powder compaction process in dies requires the determination of characteristics for use as input to the model or for confirmation of the output from the assumed model. The distributions of normal stress on work punches were determined during one-sided die compaction of a ceramic powder using all expeimental device comprised of split punches and equipped with strain gauges. The effect of presence or absence of lubrication and its influence on powder conditioning were studied. The experimental data obtained were mathematically processed using spline functions that confirmed the previous theoretical observations. The distributions of normal stress on the punches presented in this study are much more detailed than those reported in the literature. For all test cases studied, stress distribution on the upper punch shows the same shape with close numerical values. On the lower punch, the largest decrease of the normal stress is noticed when the "as received" powder is compacted without lubrication. The beneficial effect of lubrication and powder conditioning for homogeneity was demonstrated with respect to the distribution of normal stress on the lower punch. Results showed that the spline functions better represent the experimental data.