Due to the manufacturing advantages of tungsten rods, tungsten sheets, tungsten machining parts and tungsten processing equipment, Sunstone established a Division of hot zone of sapphire crystal growing since 2008. Until now Sunstone provided a large number of hot zone parts like crucibles, sheet and rods to Russia, Ukraine, USA, Japan, Korea, Thailand, Singapore Taiwan and Hong Kong. So now we have been gradually formed the capacity of 30 sets hot zone in 35Kg, 65Kg, 85Kg and 120Kg. Sunstone has a sound quality management system of ISO9001 and ISO14001 and get the certification. Sunstone has a excellent testing equipment of physical properties like density, hardness, surface roughness, grain size, tensile strength and other parameters, even ultrasonic NDT. The distinguishing characteristic of Sunstone 's tungsten crucible is high density, high purity and high precision machining. As the whole set of hot zone parts is completed in Sunstone , so the quality between the components is to get a good guarantee. With its excellent quality and reasonable price has been widely recognized by the industry of sapphire crystal growing and hot zone furnace at home and abroad, Sunstone has been designated the sole supplier and leader in domestic and foreign industry. Because of their excellent corrosion resistance again sapphire melt and their high temperature creep resistance, tungsten crucibles are used for sapphire crystal growing in all common processes. Wooden case.