Direct extrusion, also known as forward extrusion, is the most common extrusion process. It works by placing the billet in a heavy walled container with the container liners present. The billet is pushed through the die by a ram or screw. There is a reusable dummy block between the ram and the billet to keep them separated. The major disadvantage of this process is that the force required to extrude the billet is greater than that needed in the indirect extrusion process because of the frictional forces introduced by the need for the billet to travel the entire length of the container. Because of this the greatest force required is at the beginning of process and slowly decreases as the billet is used up. At the end of the billet the force greatly increases because the billet is thin and the material must flow radially to exit the die. The end of the billet (called the butt end) is not used for this reason. In the following video we can see that in the left side of the screen there are various components involved in the extrusion process which includes the pressing stem meant for forcing the dummy block against the work-piece, the initial work-piece before deformation, the cylinder walls protected with the cylinder liner inside them, the lower die block to shape up the cross section of the final extruded component, the die back up to prevent movement of the lower die. The right side of the screen shows the working of this technique. As the pressing stem is moved in downward direction the dummy block compresses the work-piece and force it move out from the smaller orifice of the lower die block with continuous and uniform force. Due to the sudden change in the cross section of the work-piece the forces acting on the lower die is higher, so it is needed to be backed up with the another block. The final component produced will be of shorter and axi-symmetric cross-section.