Hastelloy fasteners have modified content and are super alloys. These fasteners contain tungsten, nickel, molybdenum and chromium. The addition of tungsten gives hastelloy fasteners resistance towards corrosion in severe environments.
Pitting, and reducing conditions do not damage the internal structure of these fasteners. The nickel and molybdenum is added in high amounts to prevent crevice corrosion, as well. Chromium is added to these fasteners, which prevents oxidation. Carbide precipitation during welding does not occur in hastelloy, due to the low carbon content. Fasteners commercially have four main types i.e. Screws, bolts, washers and nuts. Hastelloy fasteners can withstand wide range of chemical attacks. Hastelloy can resist organic and inorganic corrosive mediums, formic acid, acetic acid, chloride solution damage, along with ferric and cupric chlorides. Pitting and stress-corrosion cracking is not a problem in hastelloy products. Applications like Reaction vessels, evaporators, chemical processing equipment, sour gas wells, paper and pulp production, pharmaceutical industry, food processing and more make use of hastelloy fasteners. Hastelloy C-276 have properties that make them some of the most widely used hastelloy grades.