The surface roughness of wood is depend on
both wood cellular structures and processing,
and one parameter can not represent all the
characteristics of the wood surface. So,
we should choose suitable parameters for
the purpose of roughness evaluation.
The arithmetical mean deviation of the profiles (Ra75) of wood specimen whose surfaces were processed by four kinds of processing changed roughly in accordance with the tactile roughness, especially when Ra75 was measured at a larger cut-off (Fig.1). The frequency power spectra of the profiles had characteristic differences among the wood species and machining processes, especially in the wavelength range under 0.25mm (Fig.2). On the other hand, there were some cases where a couple of specimens of different tactile roughness did not show any significant differences either in Ra75 or in frequency spectra. It was suggested that these differences in the tactile roughness could be characterized by the skewness and the kurtosis of the amplitude distribution of the profile (Fig.3).