The term “castings and forgings” broadly refers to metal items manufactured in foundries and forges, respectively. Examples of products falling into this category include automotive crankshafts, bearing caps, axle carriers, axle tubes, valve bodies, turbine housings, splines, suspension brackets, spring hangers, flanges, gear blanks, and more.
Foundries and forges are specialized facilities dedicated to producing entire metal parts, each employing distinct techniques. Foundries specialize in making castings, while forges focus on creating forgings. Despite the similarity in products, there is often confusion between the two terms. However, a deeper understanding of their respective processes clarifies the distinction.
In the production of castings, which typically have mid to high tolerances, manufacturers utilize closed molds, high pressure, high heat, and molten metal. This involves heating metals until they are molten and then pouring them into dies or molds, taking on the shape of the vessel. Forge processes, on the other hand, involve hot and cold hammering and stamping on solid metal pieces. Castings are formed through the manipulation of molten metal, while forgings result from the application of mechanical and thermal energy to solid metal.
Casting processes encompass permanent mold casting, grey iron casting, sand casting, rapid casting, investment casting, and die casting. Forging processes include hot forging, warm forging, cold forging, drop forging, open-die forging, impression forging, and press forging.
A variety of metals find application in both casting and forging, including steel, stainless steel, iron, aluminum, and titanium. Metals like magnesium, copper, tin, and zinc are more exclusive to casting. Apart from traditional metal casting, the process extends to materials such as plaster, plastic resin, concrete, and other chemical curing substances.
Castings and forgings each offer distinct advantages and drawbacks. While forgings typically have limitations in size and weight, there are virtually no restrictions on the potential size or weight of castings. The casting process allows for the creation of intricate and complex parts, facilitating the incorporation of additional metals during the molten stage, leading to the production of custom alloys. Forgings, however, offer tight grain structures, resulting in high wear resistance and mechanical strength comparable to expensive alloys. Forgings also address issues faced by castings, such as cavities, porosity, shrinkage, and cold pour problems.
Determining whether castings or forgings are more cost-effective in the long run is challenging, as both processes have their own sets of advantages and disadvantages. For informed advice, consulting with an experienced casting and forging sales company or manufacturer is recommended.
