Centrifugal casting, also commonly known as spin casting is typically used for industrial manufacturing of cast parts. It was the work of A. G. Eckhardt in 1809 to develop a patent showing the basic principles involved with the process. Centrifugal casting is one of the few casting processes that can be used both to manufacture metals as well as plastic parts. Parts ranging from belt buckles, medallions, figurines, and souvenirs to "pot metal" gears and machine parts, bushings, and concrete expansion fasteners are usually manufactured using this process. Spin casting or centrifugal casting is considered to be a relatively inexpensive process ranging to a total cost of no more than a $20,000 investment requirement, in comparison to a process such as investment molding that costs a lot more