E. Bousser, L. Martinu and J.E. Klemberg-Sapieha Department of Engineering Physics, Polytechnique Montreal, Montreal, Quebec H3T 1J4, Canada Solid Particle Erosion (SPE) occurs when hard particles present in the environment are entrained in a fluid stream and impact component surfaces. Since material SPE performance is determined by mechanical properties such as hardness and toughness, hard protective coatings (PC) are often used in harsh environments. However, their acceptance and further advances are frequently limited by high residual stress (RS), primarily related to the lack of fundamental and comprehensive knowledge of the stress generating mechanisms. This work will present our study on the effects of RS on the mechanical properties of hard nitride-based PC deposited using pulsed magnetron sputtering. Specifically, we investigate the effect of RS on the measurement of mechanical properties using conventional depth-sensing indentation methods compared to micro-mechanical characterization methods using micro-cantilever test specimens prepared by focused ion beam milling. We discuss the effect of coating microstructure and RS with respect to measured properties.