You can squeeze aluminum through a shaped opening, however, with the aid of a powerful hydraulic press, producing an incredible variety of useful products with almost any shape imaginable. Billet Billet is the starting stock for the extrusion operation. Extrusion billet may be a solid or hollow form, commonly cylindrical, and is the length charged into the extrusion press container. It is usually a cast product but may be a wrought product or powder compact. Often it is cut from a longer length of alloyed aluminum, known as a log.
Alloys are metals composed of more than one metallic element.
These alloying elements enhance the natural properties of aluminum and influence the extrusion process. Billet length varies according to a number of factors, including the desired length of the finished profile, the extrusion ratio, the length of the runout, and the requirements of the extrusion press. Dies and Tooling Dies can be made to form a virtually limitless array of shapes and sizes. The initial costs and lead-time of aluminum extrusion dies and supporting tools are usually a good deal lower than the tooling required for vinyl extrusion, die casting, forming, roll forming, impact extrusion, stamping or pultrusion. A typical extrusion operation will make use of a die assembly, including the die itself, which, together with a backer, is enclosed within a die ring, placed in front of a bolster, with a sub-bolster behind, all held together as a unit by a tool carrier.