How does rolling turn aluminum ingots into sheet and bar?

Rolling is the primary metalworking process used to transform cast aluminum ingots into finished products like sheets and bars.1

The process involves passing the aluminum between pairs of rollers that revolve at the same speed but in opposite directions. These rollers are spaced at a distance slightly less than the thickness of the metal, which compresses and shapes the material as it passes through.2

Key aspects of this process include:

• Multistand Mills: Modern facilities often use several stands of rolls in series. Thick metal enters the first stand, and as it passes through successive sets of rollers, it is gradually reduced to the desired thickness.21
• Temperature Control: Rolling can be performed as hot-rolling or cold-rolling. Hot-rolling increases the metal's plasticity, allowing for greater changes in thickness, while cold-rolling is often used to achieve a smoother surface, higher strength, or a thinner gauge.21
• Specialized Shapes: While sheet is the most common product, rolling mills can also be configured to press metal from multiple sides to form specific shapes, such as bars or structural beams.1