Hastelloy FastenerHastelloy 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.
Inconel fastener is an austenitic nickel-chromium based superalloy that is commonly used in extreme environments. Due to the thick protective passivating oxide layer that forms when heated, Inconel fastener can withstand immense degrees of pressure and heat that would destroy common material. Inconel fastener also retains its strength over a broad temperature range, making it highly useful for aerospace and automotive applications. Inconel bolts,nuts,screw,stud bolts are high strength that are excellent against corrosion resistance and extreme temperatures. Since the Inconel series fastener has a high corrosion-fatigue strength, high tensile strength, and resistance to chloride-ion stress-corrosion cracking inconel fasteners are used in many extreme environments such as submarines, propulsion motors, and the aerospace industry.
Monel fasteners are made from a nickel-copper alloy and exhibit high strength, toughness and good corrosion resistance over a wide temperature range. An outstanding characteristic of Monel fastener is that they offer exceptional resistance to hydrofluoric acid, a particularly tough acid to deal with, in all concentrations up to the boiling point. For hydrofluoric acid applications Monel fasteners are perhaps the most resistant of all commonly used specialty alloys. Monel 400 hex bolts, studs, and fasteners have a hardness of 65 Rockwell B, electrical conductivity at about 3.4 percent IACS, and a specific gravity of 8.83. It is easily fabricated and is strengthened by cold work.
High Temperature Alloy Fastener
ASTM A453 Covers Specification for High temperature Bolting with expansion co-efficient comparable to Austenitic Stainless Steel. One of the commonly used is grade 660 Bolts.
The specification for ASTM A453 covers five grades of bolting with twelve classes of yield strength ranging from 50 to 120 ksi (345 to 827 MPa) and is commonly used in high temperature environment such as fasteners for pressure vessels and valve flanges. The material included in ASTM A453 requires special processing and is not intended for general purpose applications.