We have measured frictional coefficients on contacting combination of stainless steel specimens immersed in liquid helium at three organizations. The measured frictional coefficients did not agree between the organizations. To analyze the difference, roughness on surfaces of the specimens were observed. In the experiments for measuring the frictional coefficients, the specimens were cooled by two method to liquid helium temperature. The difference of the cooling processes affected the frictional coefficients. Scanning electron microscopy photographs on the surfaces of the specimens were taken. The difference of the surface conditions obtained by the photographs was consistent with the measured results of the frictional coefficients.
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