ThePipingMart Blog Products SMO 254 Flanges – Composition, Properties and Uses

SMO 254 Flanges – Composition, Properties and Uses

SMO 254 Flanges

Steel is one of the most critical materials needed in different industries, and it comes in various grades depending on its intended use. Regarding flanges in petrochemicals, offshore, and marine industries, top-grade stainless steel, like SMO 254, is considered for its excellent properties. SMO 254’s primary advantage is its ability to resist corrosion and maintain strength under extreme conditions. This blog post will discuss SMO 254 flanges’ composition, physical and mechanical properties, uses, heat treatment, and corrosion resistance.

What is SMO 254 Flanges?

SMO 254 flanges are fittings used in piping and tubing systems that allow for tight connections between pipes, valves, pumps, and other components. These flanges are resistant to corrosion from seawater or chlorine-bearing compounds due to their high alloy content of stainless steel and Nickel-Molybdenum (NiMo) for superior strength and durability. These flanges can be used in various applications, including petrochemicals, industrial production plants, ships, offshore platforms, etc.

SMO 254 Flanges Composition

SMO 254 Spectacle Blind Flange is a high molybdenum steel belonging to the austenitic steel family. Its composition comprises around 6% molybdenum, 22% chromium, 20% nickel, and minimal amounts of other elements such as nitrogen, carbon, and silicon. The added molybdenum content is responsible for its superior corrosion resistance. Combining other alloying elements gives SMO 254 sheets and plates exceptional mechanical strength and toughness.

Element C Si Mn P S Cr Ni Mo N Cu
SMO 254 ≤0.020 ≤0.80 ≤1.00 ≤0.030 ≤0.010 20 18 6.1 0.20 0.7

SMO 254 Flanges Physical Properties

Grade SMO 254 Long Weld Neck Flanges have significant physical properties, which include high melting and boiling points of 1370°C and 2770°C, respectively. It has a density of 8.0g/cm3, making it one of the densest steels. It also has a thermal conductivity value of 12.4 W/mK, making it suitable for use in high-temperature applications.

SMO 254 Flanges Mechanical Properties

SMO 254 Threaded Flanges offers a high level of mechanical strength and excellent toughness. It has a tensile strength of about 680 MPa and a yield strength of around 300 MPa. SMO 254 also delivers good ductility and elongation properties, making it easy to form and shape into different flange designs.

Density Melting Point Tensile Strength Yield Strength (0.2%Offset) Elongation
8.0 g/cm3 1320-1390 ℃ 650 300 35 %

SMO 254 Flanges Equivalent

SMO 254 1.4547 S31254 2378 Z1 CNDU 20.18.06Az X1CrNiMoCuN20-18-7

SMO 254 Flanges Uses

SMO 254 flanges have various applications in oil and gas, chemical, and petrochemical industries. They are used in equipment designs that require high resistance to seawater, organic acids, inorganic acids, and chloride solutions. SMO 254 flanges are typically deployed in heat exchangers, pressure vessels, and pipe fitting applications.

SMO 254 Flanges Heat Treatment

254 SMO Flanges are normally supplied in the annealed condition with a hardness value of less than 90 HRB. If necessary, SMO 254 can be subjected to a solution annealing process, also known as heat treatment, which involves heating the material to a specific temperature and then cooling it rapidly. Heat treatment enhances the corrosion resistance of SMO 254 and improves its overall properties.

SMO 254 Flanges Corrosion Resistance

SMO 254 flanges have exceptional resistance to corrosion in different environments. SMO 254 flanges exhibit excellent resistance to crevice corrosion and stress corrosion cracking in seawater applications. It also maintains its properties under high chloride and acidic conditions. As a result, it is preferred in saltwater applications, such as desalination plants, offshore platforms, and ships.


In conclusion, SMO 254 flanges’ superior properties make them suitable for many industrial applications. They possess excellent corrosion resistance, allowing them to be used in harsh and corrosive environments. SMO 254 flanges also have high mechanical strength and good ductility, allowing them to withstand different stress loads. This steel’s physical and mechanical properties make it relatively easy to form and shape. Lastly, the heat treatment process can enhance its properties and overall performance. Contact your experienced steel distributor today to learn more about how SMO 254 flanges can benefit your industry.

Related Post