forming-manufacturing-processes > Impact Extrusion

In the Impact Extrusion process a cold slug of metal is placed in a die - the die is then impacted with a punch, the metal slug then flows around the punch filling the void between the die and the punch.

This can be achieved as "backwards" extrusion which is where the slug flows over the punch or "forwards" extrusion which is where the slug is forced through the die - following the contours of the void still between the punch and die.

This is notoriously thin walled and close tolerance with little draft angle (in comparison with cold forming in a closed die - where the component can have significant bulk and change in thickness.

Similar to both metal pressing and deep drawing in its deformation mechanism, however Impact Extrusion is achieved in a single stroke, and the depth to diameter ratios can be far in excess of what can be achieved even with deep drawing.