Tungsten is a metallic element with the symbol W and atomic number 74, belonging to the VIB family of the sixth cycle in the periodic table. Tungsten is mainly a hexavalent cation in nature, with an iron radius of 0.68 �? 10-10m. Due to the small radius of W6+ions, high electricity price, strong polarization ability, and easy formation of complex anions, tungsten is mainly in the form of complex anions [WO4] 2-, which combine with cations such as Fe2+, Mn2+, Ca2+in the solution to form precipitates of wolframite or scheelite. specification Diamter(mm) Tolerance Max length(mm) sintering,Forging,Spinning Forging and polishing 1.0-10 ±0.1 3000 10-20 ±0.1 2000 20-50 ±0.1 1500 50-70 ±0.2 1000 70-90 ±0.2 800 >90 Be customized