Impact extrusion

Impact extrusion is a manufacturing process similar to extrusion and drawing by which products are made with a metal slug. The slug is pressed at a high velocity with extreme force into a die/mold by a punch.

Process

The punch is attached to a mechanical or hydraulic press. These machines reciprocate a cycle 20 to 60 times per minute. A cold slug is placed below the punch and over the die. The punch makes contact with the slug forcing it around the circumference of the punch and into the die. The metal slug deforms to fit the punch on the inside and the die on the outside. Lubricants are also added to aid the machines benefit for an easier punch-out. It only takes one impact for the finished shape to form from the slug. Once the slug has been contoured to the desired shape, a counter-punch ejector removes the work piece from within the die.

Some Characteristics of the Process

The wall thickness of the work piece is directly correlated with the clearance between the punch and die.