Sapphire possesses excellent hardness, strength, and UV-IR transmittance properties, which make it as an excellent candidate for IR window and transparent armor material. Sapphire plate with large size grown by the Edge-defined Film-fed Growth (EFG) method appears “near-net” size, which can minimize processing cost. Recently Nanjing Tongli Crystal Material Institute Co., Ltd. has accomplished large size sapphire plate successfully by EFG method, with size up to 415 mm × 810 mm × 12 mm.