High compression forces developed during machining processes -and the subsequent energy transferred - carry on changes in the workpiece surface. These changes are usually evaluated only from dimensional or geometrical viewpoints and less frequently form the point of view of the physicochemical surface properties. Notwithstanding, some works relating geometrical and physicochemical properties of machined surfaces can be found in the literature. It is well known that geometrical features of machined surfaces are strongly related to the cutting parameters. Therefore, it can be thought that physicochemical properties of machined surfaces depend strongly on machining parameters. This work reports on the results of a study of the influence of the turning parameters on the Ultimate Tensile Strength (UTS) of turned bars of UNS A92024 Aluminium-Copper alloy.