The aluminum barrel is produced by a process called  "backward can extrusion" which is a very fast and accurate method to produce hollow specimens of metal. A stable and well controlled hydraulic drawing press is used for the process.

Figure 1 below, shows the tool setup in the hydraulic press. The “nose” and “dye” material are made of hardened, polished and coated steel. In the open position, the operator places an aluminum piece in the center of the dye. The "nose" is moved down to the aluminum piece in the dye (Figure 2) and the whiteboard marker barrel grows up vertically from the dye when the "nose" is pushed into the aluminum piece under very high pressure (Figure 3).  In a following process the thread in the barrels top is produced by rolling. 

The backward can extrusion process and the rolling processes both consume electricity.

Production of the aluminum barrel by "backward can extrusion"	Aluminum barrel produced by backward can extrusion and rolling

Main exchanges associated with production of aluminum barrel