The interface lived by weld is unavoidably to the European style of iron craftwork，it is  sure that it will effect the beauty ，but this machine can decorate the interface，it covers up the  welding joint with square or rectangle bayonet meanwhile the two kinds of bayonet appears form which is rolled by the bar mill's steel bar，it not only rises the distinction of the iron  craftwork，but also reduce man –hour of polishing .