ThePipingMart Blog Grades 304N Stainless Steel (UNS S30451) – Composition, Properties and Uses

304N Stainless Steel (UNS S30451) – Composition, Properties and Uses

304N Stainless Steel

UNS S30451 is a versatile material used in a variety of applications. Its composition, chemical properties, physical properties, corrosion resistance and heat resistance make it an ideal choice for many industries. In this blog post, we’ll delve into the details of 304N stainless steel to give you a better understanding of its uses and benefits.

304N Stainless Steel Composition

UNS S30451 is composed primarily of iron (Fe), with approximately 18-20% chromium (Cr) and 8-10% nickel (Ni), as well as trace amounts of other elements such as carbon (C), manganese (Mn), phosphorus (P), sulfur (S), silicon(Si) and nitrogen(N). This combination gives 304N stainless steel excellent strength and corrosion resistance.

Element Content (%)
Chromium, Cr 18-20
Nickel, Ni 8-11
Manganese, Mn 2
Silicon, Si 1
Nitrogen, N 0.1-0.16
Carbon, C 0.08
Phosphorous, P 0.045
Sulfur, S 0.030
Iron, fe Balance

304N Stainless Steel Chemical Properties

UNS S30451 is a uniquely powerful and versatile material, capable of providing superior performance in various applications. Its chemical properties make it ideal for use in components that must withstand exposure to corrosive media, including chlorides and alkaline solutions, as well as extremely high rising temperatures ranging from cryogenic to upwards of 1000 degrees Celsius. The composition of 304N stainless steel includes nickel, chromium, and nitrogen as primary elements, each providing its unique benefits. Chromium offers increased strength and hardness, while the higher nickel content is responsible for corrosion resistance. As an austenitic steel grade, it can be easily formed into many shapes, such as plates or tubes, with excellent weldability due to its toughness and resistance to cleavage stress cracking at ambient temperatures. These combinations of chemical properties offer 304N stainless steel proficiency in numerous industries that require materials exhibiting a high strength-to-weight ratio with excellent corrosion resistance.

304N Stainless Steel Mechanical Properties

UNS S30451 is an incredibly versatile and dependable material for various applications. Its mechanical properties allow it to resist corrosion and heat damage, making it popular in many industries. 304N stainless steel has a very high tensile strength but maintains its excellent ductility, allowing it to be easily formed into various shapes. It also has a relatively high yield strength, enabling it to withstand impacts and shocks without losing shape or breaking. 304N stainless steel is perfect for parts exposed to chemicals and extreme temperatures, as it won’t corrode or tarnish easily.

Properties Metric Imperial
Tensile strength 620 MPa 89900 psi
Yield strength 330 MPa 47900 psi
Elastic modulus 193-200 GPa 28000- 29000 ksi
Hardness, Rockwell B 85 85

304N Stainless Steel Physical Properties

The density of 304N ss is 7.85 g/cm3 with a melting point between 1454°F – 1523°F (795°C – 825°C). It has good thermal conductivity with low electrical resistivity. Due to its high strength-to-weight ratio, 304N stainless steel is also highly resistant to wear and tear.

Thermal expansion 85-41 e-6/K
Thermal conductivity 90-79 W/m.K
Specific heat 450-460 J/kg.K
Melting temperature 5305-5983 째C
Density 3384-2207 kg/m3
Resistivity 0.50-0.60 Ohm.mm2/m

304N Stainless Steel Equivalent

ASTM A182 ASTM A193 (B8N, B8NA) ASTM A194 (8N, 8NA) ASTM A213 ASTM A240

304N Stainless Steel Uses

304N ss is an austenitic metal alloy with superior corrosion and oxidation resistance. It has a wide range of applications in manufacturing automotive parts, semiconductor equipment, heavy machinery, kitchen appliances, and medical instruments. Because 304N stainless steel can withstand high-temperature environments, it is often used to produce exhaust manifolds and pipe fittings. Its good mechanical strength makes it suitable for architectural components that require durability. With its aesthetic appearance and ability to resist tarnishing over long periods of time,304N stainless steel has become a popular choice for jewellery makers looking to create luxurious designs while also minimizing environmental impact.

Corrosion Resistance

The chromium content in 304N stainless steel gives it great corrosion resistance against acidic environments like swimming pools or hot tubs. In addition, its low carbon content provides excellent resistance against intergranular corrosion that can occur when welding or machining the metal.

Heat Resistance

Because it contains so much nickel, 304N also has excellent heat resistance up to 1500°F (816°C). This makes it suitable for use in applications exposed to high temperatures, such as boilers and furnaces.

Heat Treatment

304N stainless steel does not need heat treatment before machining; however, it can be annealed if desired. It can be machined using conventional tools like drills and taps but should be done slowly due to its hard nature. When welding with 308L, filler metal should be used for the best results.


Machining 304N stainless steel can yield great results, especially in wear and corrosion resistance. This metal is often used for industrial tools because of its hardening strength and ability to resist rust. Cutting speed and tool life are important factors to achieve quality parts from machining 304N stainless steel. With plans such as increases in feed rates, lower depths of cut, proper lubrication and coolants, these features may be optimally achieved. By considering all aspects of production, machined 304N stainless steel can provide superior output and reduce costs associated with machining over other metals.


Welding 304N stainless steel is incredibly important for creating safe and reliable metals. It is commonly used to create bridges, cranes, and various other forms of machinery and structure due to its impressive tensile strength, corrosion resistance, and weldability. Whether using manual or robotic welding processes, ensuring that all safety protocols are followed when working with any steel is important. Professional welders need to be aware that extreme heat needs to be applied to 304N for welding to occur properly; if the heat isn’t at the correct level, it can be impossible for a solid join to form. However, professionals should have no trouble securely welding this stainless steel for years of use with the right tools and methods.


304N Stainless Steel is an ideal choice for many industrial applications due to its composition, chemical properties, physical properties, corrosion resistance and heat resistance capabilities. Its versatility allows it to be used in numerous industries, from food processing equipment to boilers and furnaces, without sacrificing quality or performance. Its ability to withstand extreme temperatures makes it ideal for high-temperature applications. At the same time, its low carbon content ensures that welds remain strong even after cooling off from welding operations. All these advantages and affordability make it a go-to option for businesses looking for reliable alternatives in their production processes!

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