An experimental study of the effects of residual elements in carbon steels was carried out to gain better understanding and control of the effects of residual elements emanating from recycled steel scrap. Two plain carbon steel grade compositions (one medium-carbon and one low-carbon), residual elements and levels, and four areas of study, were selected on the bases of a comprehensive literature survey and consultation with sponsor steel companies. The influence of residuals (Cu, Sn, Ni, P, Si, up to the levels studied here), on these laboratory produced hot rolled steels was studied in the areas of (1) hot ductility, (2) surface hot shortness, (3) scale formation and adherence, and (4) embrittlement and mechanical properties. This report summarizes the experimental procedures, results, discussion and conclusions of this study. The relevance of the study is also discussed in relation to steel processing and product properties and in relation to energy consumption and environmental compliance.