This paper presents a study of the wear of high-speed steel cutting tools modified mechanochemically by shot peening their rake faces with a mixture of Al2O3 and Cu2S particles. This treatment has been recently proved to reduce cutting forces significantly, but little is known about the wear resistance of the modified tools. To pave the way for practical implementation of this technology, here we bridge this gap. Orthogonal cutting tests performed under base oil lubrication demonstrate at least a twofold increase in the tool life compared to the untreated references. This is attributed to the formation of iron sulfide and its ability to retain oil at the cutting interface, which results in lower stresses and temperature. This environmentally friendly technique shows good potential to lower manufacturing costs, reduce energy consumption, and improve machining quality.