Initial counterface topography influences both running-in and steady state wear rates of polymers. But governing roughness parameters are difficult to isolate because of their strong dependences and their statistical natures. Distributions of RT, RA, R.M.S., Skewness, Kurtosis, profile slopes, number of peaks per unit length, radii of curvature of peak asperity and Fourier transform were considered to characterize the isotropic roughness of the abraded steel disks. Two polyimide composites with PTFE and CF x powders were chosen for the pins. Correlations between parameters, friction and linear steady state wear were obtained through statistical data analysis. Radii of curvature, profile slopes or RA, and number of peaks govern friction and wear in different ways depending on fillers. However, for both materials, wear increases with average slopes or RA and decreases with an increase of number of peaks and radii of curvature. Skewness governs also the results but Kurtosis and wave length of the maximum of the Fourier transform are useless to explain the results.
