The technology of IKUTA in copper elongation line is also esteemed except milling process. With degreasing pickling buff polishing line, the beautiful finished surface which suppressed the chatter mark extremely can be realized. High evaluation has been obtained by the production of high-precision equipment. The points of raising the precision of equipment are high precision buff polishing equipment which suppressed vibration by pursuing stable rotation, and analyzing about vibration of a buff, and a polish portion by IKUTA, as well as using the high quality axis and bearing parts all made by captive factory carefully.