The melting point of tungsten bars is 3500 ℃, and the purity of tungsten bars should usually be above 99.95%. The sintering temperature of tungsten is 2500 ℃, and the density is 17.5g/cm3. The sintered tungsten bars can be provided in the following specifications: square bars (10-16) * (10-16) * L ≥ 30mm; Round bar Dia (16-30) * L ≥ 30mm, current national standard GB/T 3459-2006, grades W-1, W-4, the difference is reflected in the purity and impurity content, especially the content of O, C and Fe. W-1 can be used as pure tungsten and tungsten alloy products, while W-4 is mostly used for steelmaking.