Tungsten(VI) fluoride, also known as tungsten hexafluoride, is the inorganic compound of tungsten and fluorine with the formula WF₆. This corrosive, colorless compound is a gas under standard conditions, with a density of about 13 g/L (roughly 11 times heavier than air.), WF₆ is one of the heaviest known gases under standard conditions. WF₆ gas is most commonly used in the production of semiconductor circuits and circuit boards through the process of chemical vapor deposition – upon decomposition, molecules of WF₆ leave a residue of metallic tungsten. This layer serves as low-resistive metallic "interconnect".

At ambient pressure and temperatures above 17 °C, tungsten hexafluoride is a colorlessdiamagnetic gas. The WF₆ molecule is octahedral with the symmetry point group of O_h. The W–F bond distances are 183.2 pm. Between 2.3 and 17 °C, tungsten hexafluoride condenses into a pale yellow liquid having the density of 3.44 g/cm³ at 15 °C. At 2.3 °C it freezes into a white solid having a cubic crystalline structure, the lattice constant of 628 pm and calculated density 3.99 g/cm³. At −9 °C this structure transforms into an orthorhombic solid with the lattice constants of a = 960.3 pm, b = 871.3 pm, and c = 504.4 pm, and the density of 4.56 g/cm³. In this phase, the W–F distance is 181 pm, and the mean closest intermolecular contacts are 312 pm. Whereas WF₆ gas is one of the heaviest gases, with the density exceeding that of the heaviest elemental gas radon (9.73 g/L), the density of WF₆ in the liquid and solid state is rather moderate. The vapor pressure of WF₆ between −70 °C and 17 °C can be described by the equation

where the P = vapor pressure (bar), T = temperature (°C).

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