Tungsten as electrical contact or contact sub material, resistant to arc ablation; good melting resistance; metal surface evaporation caused by electric heating, less transfer and consumption; strong blocking current ability; and has good wear resistance, dynamic performance. Compared with other metals or alloys, tungsten contacts and tungsten wafers are widely used in industry, agriculture, science and technology and national defense. Tungsten contacts are widely used in ac contactor contacts, car speakers, electric speakers, magneto and other electrical products.