You're probably familiar with the classical bronze casting of the ancient world, which was responsible for creating many weapons, tools and pieces of art that are still around today. Casting is a way of transforming molten metal into unique and complex shapes by pouring it into a mould. Once the metal has cooled and solidified it is removed from its mould, and the moulded metal is refined to remove the runners and risers created to ensure the material filled the entire mould.
While many metals and alloys can be cast, bronze casting stands out as the Bronze Age gave rise to bronze castings that reflected the religious and social makeup of cultures from all over the world. Bronze, an alloy formed from copper and tin, is thought to have been discovered sometime between 4000 and 3000 BCE. Because it was more hard-wearing than either pure copper or tin, bronze soon rose to prominence, and today's historians and archaeologists benefit from still-intact Greek castings depicting the human body, Indian religious castings and Chinese castings recreating ceremonial scenes, all in bronze.
What is fascinating about these ancient pieces is that the techniques early artisans relied on continue to underpin our society in surprising ways. In fact, 90% of goods manufactured today still depend heavily on the centuries' old technology of metal casting. While the process itself is relatively simple, casting has stood the test of time because it allows manufacturers to cost-effectively create highly unusual and technical shapes.
Die casting is a relatively modern invention that arose with innovations in the printing industry in the 19th century. The process relies on molten alloys of zinc, tin, aluminium, lead, copper or bronze, and the material is forced into moulds under high pressure. Die casting delivers consistency of output and a surface finish far superior to that rendered by other forms of casting, and die casting in bronze offers the opportunity to create durable and unique surface finishes while working to interior specifications with great accuracy. The cost of die casting moulds is high, as they must be formed from hardened steel, however the accuracy of the process minimises the need for post-fabrication machining, leading to shorter production times and greater cost-efficiency in the long term.
Although the casting process continues to evolve alongside technical developments and breakthroughs in research, it is important to keep one eye on the past, and thank the ancients for this incredible innovation.