Experiments involving the manufacture and use of stone tools are described. The original tools that served as models came from two sites in upper bed IV at Olduvai Gorge, Tanzania. The following conclusions are drawn. Widespread use of terms such as ‘crude’ or ‘refined’ in describing stone tools tells us nothing of the technical level achieved by the makers of the assemblages. The different qualities of the available raw materials, the forms in which they occur and how they function when used may have influenced the tool maker’s designs and the morphology of the tools. The experiments suggest uses for the tools that are relevant to our understanding of what is found on some archaeological sites.