<p>Wedge-shaped tools have been widely used in both field and laboratory settings for rock indentation; however, the mechanical responses associated with wedge-shaped indenters featuring varying geometric parameters—such as inclination angle and tip width—remain largely unexplored, both experimentally and theoretically. This is particularly true when considering the interference of specimen size effects on the interpretation of test results. In this study, we conducted indentation tests using wedge-shaped indenters with different geometries on rock specimens of varying sizes. The experimental results demonstrate that specimen size and indenter tip width exert opposing effects on peak indentation pressure, with an increase in either parameter leading to greater total energy input. In the accompanying theoretical analysis, we validated a cavity expansion model originally developed to analyze indentation across specimens of different sizes. The model predictions closely align with experimental data regarding the size effect induced by the tip width of the indenters on mechanical responses. Finally, we discuss the implications of these findings for optimizing tool shape using the cavity expansion model.</p>