In general, metal is a very hard, tough, and strong material. It’s used to manufacture construction girders, bridge beams, automobiles, airplanes, tanks, and countless other rugged items (not to mention plenty of smaller, daintier ones like the casing of your smartphone). But as it is such a heavy-duty material, how the heck does one form metal into the specific shapes needed to create such things?
Let’s take a brief look at three of the most common “industrial” metalworking methods.
One method of forming metal is stamping. Using huge, usually hydraulically-powered presses, parts of all sizes and shapes—from the simple to the highly complex—are stamped out of metal sheets. These sheets can be up to ½” thick or thicker, in some cases. Like a cookie cutter punching shapes out of dough, these presses use specially-made tooling to cut through the metal, resulting in separate, perfectly-shaped pieces.
Any metal stamping manufacturer worth its salt will utilize punch presses with multiple-ton capacities. The tonnage of these machines relates to the equivalent pressure they’re able to exert when stamping a part—a 50-ton press, for example, can produce the equivalent of 50 tons of downward force. Most modern stamping presses are computer-controlled so as to provide greater efficiency and accuracy.
Forging is a metal manufacturing process that uses molten metal to create the final form. After being heated to a red-hot state, metal is poured into molds (also called “dies”) that provide the shape of the components. Pressure is often applied to ensure that the near-liquid material properly fills in all the open spaces of the mold.
Another method, called open-die forging, forgoes the use of molds. Instead, this method sees the heated metal being pressed into the desired shape by external tools. These tools require both significant pressure and a good bit of finesse to accurately produce the final shape of the metal part.
Drawing is similar to stamping, except instead of punching all the way through, the process instead stretches and deforms the metal sheet into the desired shape. Multiple passes are often required to achieved the desired shape, especially for “deeper” components—that is, components that are significantly taller than they are wide or round. For each pass, a different drawing die (that word comes up a lot in metalworking) is used, each bringing the piece progressively closer to its final form.