Plants to produce small metal alloy of zinc or tin by centrifugal casting. It involves the use of silicone rubber for the preparation of molds, as negative counterform obtained from the original positive, to be filled subsequently by casting, using some materials such as white metal alloys, low melting point, or the resins (epoxy, polyurethane or polyester), gypsum, etc.. The plants performs the realization of buckles, jewels, buttons and fashion accessories.