Aluminum Bars
Aluminum bars are straight, uniform aluminum products that are usually circular, but may have many differently shaped cross sections. Their diameter is many times longer than width and they are used in the electrical and construction industries. Aluminum bars often make shafts, railings, stakes and tines. These simple shapes are made from heated aluminum billets by extrusion under high pressure through a die with a specific bar shape. Bars are similar to rods, but they differ in variety of shape. Rods are the basic round shape, while bars may be square, rectangular, triangular, flat and hexagonal.
Billets made from aluminum, which are semi-finished bar stock, go through extrusion to become bar-shaped. They are heated to 900 degrees F, placed in an extrusion press and drawn. Drawing refers to pushing the billet through a steel die by a large, hard metal ram under forced pressure. They are often pushed through consecutively smaller dies multiple times in order to reduce their cross section a little at a time. Larger bars may only be extruded once, while small bars are often put through the process more than twice. Liquid nitrogen is often poured after the bar is extruded to cool the temperature. Although many bars require no sort of cold working, those that are exhibit an improved surface finish and dimensional tolerances.