Everywhere we go, investment merger is involved in some way. The reason for this is that parts developed in investment casting are used in everything from ships to manual clocks and everything in between. Whether you've traveled, played golf, or even gone to the doctor for an operation, chances are you've used parts made from investment casting. As you might imagine, investment casting has many modern uses but has been around for more than 6,000 years. Over the centuries it has been exploited to produce objects such as jewellery, sculptures and even weapons. Although investment casting dates back to the early 2nd century, the development of investment casting as a manufacturing method began approximately in the mid-20th century. Since then, the industry has grown steadily. Around the year 3200 BC, the oldest casting known to man, a copper frog is smelted in Mesopotamia. 200 years later, the first smelters cast bronze tools and weapons in permanent stone molds. Fast forward a few centuries later, in the year 600 BC, the Chinese produce the first cast iron object, it is a 600 pound tripod. Sand is introduced as a modeling material in France. In the year 1619, North America builds its first iron furnace located in Falling Creek, Virginia. In 1709, a man named Abraham Darby of Coalbrookbale, England improved casting methods by developing the first true foundry flask to modernize molding practices. Previously, it was done in pits from the floor using drawing boards tied together. His other contribution to the profession was the initiation of the use of coke as a fuel in the iron production process. In 1809, A. G. Eckhardt of Soho, England, developed the centrifuge... the center of the paper... tuccoing. The process is then repeated until the required thickness is reached, usually between 5 and 15 mm. it is then left to harden. Note that the first few layers are known as main layers. The wax is then removed in a steam autoclave which takes approximately 16-48 hours to dry and the ceramic shell is fired. Once the wax has melted from the ceramic mold, the molten metal is then poured into the ceramic shell using a transfer ladle. After the molten metal has cooled and finally solidified, the shell is removed by vibrating methods, hammering, or chemically melting the shell, and the finished casting looks exactly like the original wax pattern. The casting will then be cleaned by grinding to remove signs of the casting process and then subjected to a series of rigorous quality control tests to ensure a quality product to the customer.