How to determine the number of asperity peaks, their radii and their heights for engineering surfaces: A critical appraisal

► Asperity-peak properties were analysed for a broad range of engineering surfaces. ► Asperity-peak properties greatly depend on asperity-peak identification criteria. ► Data resolution in the x-direction (Δx) has a large influence on the asperity-peak properties. ► Δx distances above 1 μm seem to be less appropriate for asperity-peak identification. ► A 3-point peak criterion is proposed for asperity-peak identification.