Abstract
Previous works have showed that the phosphate treatment is an excellent method of frictional surface treatment. However, it has not yet to be studied as to how much the scattering range of slip coefficient, when this method is applied . In this report, the reliability of the phosphate treatment based on the scattering range of slip coefficient after conducting a slip coefficient test as many as 192 times have been examined.As the result, it has been turned out that the phosphate treatment is a fully reliable method.
