This bi-monthly series features entries from the well-known designer’s handbook, Making It: Manufacturing Techniques for Product Design, 2nd Edition, published by Laurence King Publishing at www.laurenceking.com. Each column describes a material used in design and/or the processes for its use.
Impact extrusion is a cold process for forming metals that marries forging with extrusion. In a nutshell, backward impact extrusion is a method of forming hollow metal parts by striking a metal billet (or disk), which is confined within a cylindrical or square die, so hard that the metal is forced upward into the space between the “hammer” (or punch) and the die. The gap between the punch and the inside of the die determines the wall thickness of the final component.