The reactions of tungsten hexafluoride (WF6) on stainless steel, tantalum, platinum, nickel, and Monel 400(R) were investigated using temperature-programmed desorption and Auger electron spectroscopy in ultrahigh vacuum. The high reactivity of stainless steel and tantalum surfaces indicate that they are not suitable materials for tungsten chemical vapor deposition reactors. Nickel and Monel 400(R) are much less reactive and are suitable for use below 800K. Platinum does not react with WF6 below 600K and may be suitable for use at higher temperatures. Mass spectrometer cracking patterns for WF6, WOF4, and WO2F2 were measured.