Hastelloy alloy fastener has excellent resistance to a wide variety of chemical process environments, including strong oxidizers such as ferric and cupric chlorides, hot contaminated media (organic and inorganic), chlorine, formic and acetic acids, acetic anhydride, and seawater and brine solutions. It is often used in flue gas desulfurization systems because of its excellent resistance to sulfur compounds and chloride ions encountered in most scrubbers. Hastelloy alloy fastener has excellent resistance to pitting and to stress-corrosion cracking. It is also one of the few materials that with stands the corrosive effects of wet chlorine gas, hypochlorite, and chlorine dioxide. Hastelloy can be fabricated by a variety of Methods. Hastelloy alloy fastener can be forged, hot-upset, and impact extruded. Although the alloy tends to work-harden, it can also be successfully deep-drawn, spun, press formed or punched. Since it is a strong material with corrosion resistances, it has been used in nuclear and chemical reactors and also in valves and pipes in the chemical industries. The most common Hastelloy used in fasteners is C276, B, C-4, G, C-2000, X and C22.