A rotary reduction of fine wires/tubes of a wide range of diameters using a pair of concave rolls

This paper presents an innovative rotary reduction method of elongated fine solid wires and hollow tubes, the diameters of which could be reduced to 0.02 times of diameter of rolls as the tool. A pair of concave rolls is positioned at a skew angle to the material axis, and the rolls compress the material. The material travels between the rolls in a spiral movement with tension applied on its ends. The method is applicable for a very wide range of diameters using the same tools. Diversified shapes would be fabricated as the method reduces the diameter at arbitrary axial positions.