Alloy steel flanges are made of a combination of iron and other alloying elements, such as chromium, molybdenum, nickel, and vanadium. These elements are added to improve the strength, toughness, and corrosion resistance of the steel. Alloy steel flanges are typically used in applications where there is a high risk of corrosion or where the flanges need to be able to withstand high pressures or temperatures. Alloy steel flanges are available in a variety of types, including: Weld neck flanges: These flanges have a welded neck that allows them to be welded to a pipe. Slip-on flanges: These flanges slide over a pipe and are secured with bolts. Socket weld flanges: These flanges have a socket that is welded to a pipe. Lap joint flanges: These flanges have overlapping faces that are bolted together. Blind flanges: These flanges have a closed face and are used to seal off a pipe. â?¢ Alloy Steel Flange : ASTM A182 / ASME SA182 & A387 F1, F5, F9, F11, F12, F22, F91 Flanges