Metal Refinement- A Closer Look Metal Refinement is a technological advancement that had a tremendous effect on modern society, including the automotive industry. Though all the talk in the industry today is of carbon fiber and alloys, metal is probably the most important, abundant, and inexpensive material used for the construction of our vehicles and for the development of stronger and lighter materials. The most common terms in reference to metal formations are casting, forging and billet. These terms do not refer to the metal itself, but to how it is refined to develop the part being produced.

CASTING Casting is a process of forming metal parts by pouring molten metal into a cast or mold and letting it cool. Metal casting is one of the oldest techniques used to refine metal and is still widely used in today’s manufacturing.

FORGING Forging is a process of forming metal parts in molds called dies by the use of heat and pressure. A piece of metal is placed between the two halves of the mold and then pressed together. The stationary half of the mold is called a “die” and the moveable half is called a “tool”. Forging develops a grain structure in the metal, which increases the strength in the direction that it has been stretched. This technique makes a forged part stronger than a cast or billet part. Manufacturers now use several different techniques to forge metal. The chart below lists the four most common techniques.

BILLET The term billet- known to many as manufacturer’s brand name or type of metal- is actually a solid piece of metal typically in the form of a slab or a section of round stock. The billet is commonly cut into the desired part with the use of a CNC (Computerized Numerical Control) machine. CNC is the term used to refer to modern milling machines that can shape complex parts from solid billets. Though CNC machined parts in high demand, they are not as strong as forged parts, they waste a large amount of excess material, and they are not time-efficient as the traditional methods of refining metal. Compared to forging or casting, machining with a CNC is more time consuming due to the complexity of the shapes and details that certain parts entail.
Purchasing a metal-made product will be much more simple in the future, by gaining a better understanding of how different metal processes work in conjunction with job that it calls for. The next time you purchase a metal part, determine how it was made and you should be able to determine if the part will meet your needs.