With a melting point as high as 3,410℃, tungsten crucibles are extensively applied as core container inside industrial furnaces like sapphire crystal growth furnaces, quartz glass smelting furnaces and rare-earth smelting furnaces, and their ambient operating temperature reaches 2000℃ or higher in most cases. Especially for sapphire crystal growth furnaces, the tungsten crucible, which is characterized by high purity, high density, precise dimensions and bright and clean inside and outside walls free of internal tearing, is essential for guaranteeing the crystal-seeding success ratio, crystal pulling quality control, de-crystal crucible affixing and service life in process of sapphire crystal growth.