It has been a popular practice to apply the blast treatment to the frictional joint of the hot dip galvanized steel . However, this method is never free from any problems in terms of the cost, the quality ( peeling of hot dip galvanized coating ), and the delivery date. For this reason, we have taken up in our study the phosphate treatment and the ceramic coating as a method of frictiona surface treatment that can be applied easily. A s a result, it turned out that the phosphate treatment was an excellent frictional suface treatment, whereas it turned out that the ceramic coating suffered some problems.
