Abstract: The traditional machining method on fabricating spur gears has much defects compared to the precision forging process. The current upset-extrusion process is difficult to utilize in industry due to its overlarge deformation load. The performing divided flow region and final forging process is proposed. A set of experimental tools with much combination of inserts is designed and used to perform the new process and the upset-extrusion process using tube billets and cylindrical billets, respectively. The experimental results show that the new process can not only achieve the spur gears with full teeth and smooth end surface but also reduce deformation load more than 37%. The new process has potential for future industry application.

Key words: Experimental study, Precision forging, Spur gear