With a process similar to that of extrusion and drawing, impact extrusion uses a metal slug in production. At a high velocity the slug is pressed into a die or mould with extreme force, using a punch that is attached to a mechanical or hydraulic press.
The impact extrusion machines can reciprocate a cycle from 20 to 60 times per minute. The punch makes contact with the slug, which is placed below the punch and over the die, and forces it around the circumference of the punch and into the die. The metal slug deforms and fits itself to the punch on the inside and the die on the outside. For an easier punch-out, lubricants are also added. It takes only one impact for the slug to form the finished shape. After the slug has taken the desired shape, the work piece is removed from within the die by a counter-punch ejector.
Impact metal extrusion units in Indiaproduce end products that have a better surface finish than the starting piece. The grain of the material is also reformed to its new shape, adding strength to the new form as compared to a machining process.