Impact extrusion is one of the cold forming processes used for the larger sized products. The process starts with a volume controlled “slug” contrary to the cold heading process that starts with a wire.
Stalcop impact extrusion capabilities currently include diameters up to 4 inches and lengths up to 16 inches handling volumes from 1,000 to multi-million pieces per year. These capabilities are not restrictive as our investment focus on new opportunities to meet our customers needs.
The most common impact extrusion techniques are — “forward extrusions” and “backward extrusions.” The creativity the design engineer can enable both of the techniques to be used simultaneously to minimize production cost as many designs include both extrusions.
The extrusion process is one of the cold forming techniques forcing the material to flow in the open space between a die and a punch. In this technique, the material can move either forward (forward extrusion) or backward (backward extrusion) however, many products use a combination of both extrusion (combined extrusions).
Material is forced forward by the punch through an orifice in the die, producing a smaller cross section than the initial blank. 75% reductions are possible with this technique.
Material is contained in the die and forced backward around the punch, producing blind holes and cups. The bottom of the cup should be thicker than the walls. Area reductions of 20-75% are possible with this technique.