Refractory and reactive metals include boron (B), tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb) / columbium (Cb), zirconium (Zr), hafnium (Hf), thorium (Th), vanadium (V), chromium (Cr), cobalt (Co), rhenium (Re ), and titanium (Ti).

Refractory metals and alloys are metals with melting points above ~1750 C (~ 32000 F). They are used in high temperature, structural, electrical, and other specialty applications.

Reactive metals combine readily with oxygen at elevated temperatures to form very stable oxides. Titanium, zirconium, and beryllium are considered reactive metals. Finely divided reactive metals can react explosively with oxygen and are often added to rocket fuels or combustible mixtures. A highly stable oxide film formed on the alloy surface provides protection against further oxidization or corrosion at low to moderate temperatures. Reactive metals can become embrittled if there is too much interstitial absorption of oxygen, hydrogen, and nitrogen into the lattice.