A new forming method of solid bosses on a cup made by deep drawing

A new process for forming bosses on the bottom of a cup made by deep drawing is proposed: solid bosses are formed by compression of the cup bottom during deep drawing. By the combined effect of compression and deep drawing, bosses are formed with a lower load than simple compression or backward extrusion. It is found that high bosses can be formed with moderate punch pressure when only one side of the blank is lubricated.