The chemical process industry utilizes many different materials of construction to contain and to instrument the many varied and often aggressive chemical processes. Molybdenum, niobium, tantalum, and tungsten, known as the refractory metals, see limited use in the chemical process industry. A summary of the corrosion resistance, mechanical properties, fabricability, economic factors, and special properties of the refractory metals for chemical process applications is given. The various refractory metals are compared to more traditional materials used in the process industry.