Abstract: CVD-diamond for dry drilling applications is reported. Specifically, the fabrication of nanostructured diamond coated drills is outlined. Tool life is evaluated by dry drilling of aluminum alloy and nanostructured diamond coated drills show a superior performance to uncoated drills. In addition, different surface treatments have been studied with the effects on diamond film deposition and delamination investigated. Moreover, drill edge geometry has been evaluated. Major findings indicate that the drill edge radius plays a critical role to the drilling performance. A slightly honed edge may lead to improved performance due to the reduction of deposition stresses at the tool edge.