Because temperature in tin furnace is more than 260 degree. The jig material is required to be not 
out of shape. Or the PCB board will be useless and lead to big loss. The physical property of Durostone
meet this requirement. Taking material cost, machining properties and high temperature resistance 
into consideration, Durostone material is the best choice. But Durostone material from Germany is 
too expensive, most of jig processing companies in China used durostone equivalent that made 
in China to replace Durostone that made in Germany. The factories that can producing Durostone
equivalent in China are just a few.