Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Surface modification of high-speed steel drills using laser has been proposed as a step before physical vapour deposition in order to increase the adhesion of the titanium nitride coating on the tool substrate. A copper vapour laser and a scanning-head system were used to produce highly controlled laser ablation on the surface. In the current work, the laser average power varied from 0.5 to 6 W and the laser shots were applied next to one another. After laser surface modification and coating, the drills were used to machine low-alloy carbon steel and stainless steel in a CNC machine. The tool lives were then compared to those obtained with the same kind of tool but whose substrate was prepared conventionally. The laser-treated drills had a longer lifetime than conventional ones. Under the conditions of this study, the laser-treated drills presented a 40% higher performance than conventional drills for carbon steel machining. The increase in performance reached 400% in stainless steel drilling. In general, laser processing with an average power of 1 W yielded the best results.O TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE FEVEREIRO DE 2015.54170098115Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [310761/2009-3]FAPESP [2007/08265-2]