Tungsten carbide nozzle has a high melting point at 2,870 °C (5,200 °F), a boiling point of 6,000 °C (10,830 °F) when under a pressure equivalent to 1 standard atmosphere (100 kPa), a thermal conductivity of 110 W/mK, and a coefficient of thermal expansion of 5.5 µm/mk. Tungsten carbide nozzle is extremely hard, ranking 9 on Moh's scale, and with a Vickers number of 2600. It has a Young's modulus of approximately 530–700 GPa, a bulk modulus of 630–655 GPa, and a shear modulus of 274 GPa. It has an ultimate tensile strength of 344 MPa, ultimate compression strength of 2.7 GPa and a Poisson's ratio of 0.31. The speed of a longitudinal wave (the speed of sound) through a thin rod of tungsten carbide is 6220 m/s. With a low electrical resistivity of (~2×10−7 Ohm•m), tungsten carbide's resistivity is comparable with that of some metals (e.g. vanadium 2×10−7 Ohm•m).
WC is readily wetted by both molten nickel and cobalt. Investigation of the phase diagram of the W-C-Co system shows that WC and Co form a pseudo binary eutectic. The phase diagram also shows that there are so-called η-carbides with composition (W,Co) 6C that can be formed and the fact that these phases are brittle is the reason why control of the carbon content in WC-Co hard metals is important.