Forming characteristics of tubular product through the rotary swaging process

Experiments for the forming characteristics of a tube by a rotary swaging process have been carried out to obtain a tubular product of desirable quality taking into account the process variables such as the forming feed and reduction of diameter of the product using the developed rotary swaging machine and four-split dies. From these experimental results, it is found that the process variables affect the quality of the tube such as the dimensional precision, hardness, surface roughness and microstructure of the product. It is also found that defects can occur at the forming feed of more than 2.0 mm/rev. The thickness of the product increased about 63% from its initial thickness of 2.3 mm to 3.75 mm. The hardness measured on the surface of the tube depended on the reduction of the diameter and is rarely affected by the variation of the forming feed from 0.5 to 2.0 mm/rev. The surface roughness of the product after swaging is about three times better than that before swaging. Based on these results a tubular rod shift for an automobile steering part was shown to be effectively manufactured by the rotary swaging process.