Duplex Steel Nuts are made of a combination of elemental iron, chromium and nickel, as well as other metals such as molybdenum and nitrogen. The proportion of elements in the steel varies depending on the grade or type of Duplex Steel Nut, the most popular grades being 2205 and 2507. They generally contain around 22%-26% chromium and 4-6% nickel. Compared to traditional stainless steel fasteners, Duplex Steel Nuts possess superior corrosion resistance properties thanks to their Duplex Structure, which gives them distinct properties. This structure ensures higher strength due to its ferritic-austenitic microstructure, which produces an increased content of austenite in the alloy enabling improved mechanical strength when compared to conventional bolts.
Duplex steel nuts are widely used due to their excellent strength and corrosion resistance combination. The steel is composed of austenite and ferrite microstructures, creating a material stronger than 316 austenitic stainless steel. This makes them ideal for applications exposed to corrosive environments or high mechanical stress, such as chemical reactors, petrochemical tanks or pulp mills. In terms of strength, duplex stainless steel nuts can handle anywhere from 1.5 to 4 times more axial tension than regular nuts, making them invaluable for situations requiring maximum performance. In addition to their strength and corrosion resistance properties, Duplex Steel Nuts also possess high hardness, good energy absorption capacity and hot workability. Finally, they come in many different sizes and shapes, so one can easily find the right nut for their particular application.
Duplex steel nuts are available in a variety of sizes, ranging from M1.6 to M100 in diameter and with lengths up to 180 mm.
Duplex steel nuts are commonly used for marine, oil & gas, and chemical industry applications due to their superior strength and corrosion resistance compared to other types of steel. These nuts are also popular for structural applications due to their high-pressure ratings and temperature tolerance.
The pressure rating for duplex steel nuts is usually between 1,300MPa and 1,700MPa at room temperature.