ThePipingMart Blog Grades 904L Stainless Steel (UNS N08904) – Composition, Properties and Uses

904L Stainless Steel (UNS N08904) – Composition, Properties and Uses

904L Stainless Steel

Are you looking for a steel alloy with excellent corrosion resistance, is non-magnetic, and can handle extreme temperatures? If so, then 904L stainless steel might be ideal for your needs. This type of stainless steel is often used in applications with exposure to highly corrosive environments, as it offers superior corrosion resistance compared to other alloys. Let’s take a look at the composition, mechanical properties, physical properties, and uses of 904L stainless steel.

904L Stainless Steel Composition

UNS N08904 is an austenitic grade alloy containing roughly 23% chromium, 19% nickel, 4.5% molybdenum, and a small amount of carbon (less than 0.2%). It has low carbon content, which makes it highly resistant to intergranular corrosion following welding or stress-relieving operations.

Grade C Mn Si P S Cr Mo Ni Cu
904L min.















904L Stainless Steel Mechanical Properties

UNS N08904 has good formability and weldability characteristics due to its low carbon content. It also offers good toughness and strength at both room temperature and elevated temperatures. Additionally, it exhibits excellent fatigue strength even after prolonged exposure to high temperatures.

Grade Tensile Strength (MPa) min Yield Strength 0.2% Proof (MPa) min Elongation (% in 50mm) min Hardness
Rockwell B (HR B) Brinell (HB)
904L 490 220 36 70-90 typical 150

904L Stainless Steel Physical Properties

This type of steel has good ductility and excellent machinability properties, which make it easy to work with when fabricating parts or components from this material. It also has excellent thermal expansion properties, making it suitable for cryogenic environments or high-temperature applications where thermal shock can occur.

Grade Density
Elastic Modulus
Mean Co-eff of Thermal Expansion (µm/m/°C) Thermal Conductivity
Specific Heat 0-100°C
Elec Resistivity
0-100°C 0-315°C 0-538°C At 20°C At 500°C
904L 7900 190 15 11.5 500 952

904L Stainless Steel Uses

Due to its superior corrosion resistance properties, this type of stainless steel is often used in applications such as oil refineries, chemical processing plants, pulp & paper mills and desalination plants where there may be exposure to highly corrosive environments. It is also commonly used in marine engineering applications due to its excellent resistance to salt water corrosion and its non-magnetic properties, making it suitable for underwater applications such as sonar domes on submarines. Additionally, this alloy is often used in medical instruments due to its biocompatibility characteristics, making it safe for contact with human tissue or fluids without causing any adverse reactions.


As you can see from the information above, 904L stainless steel offers many benefits that make it an ideal choice for many industries, including the oil & gas industry, marine engineering industry, and the medical instrumentation industry, among others. Its superior corrosion resistance properties and ability to withstand extreme temperatures make it an ideal choice for many different applications where traditional steels may not be suitable due to their inability to withstand highly corrosive environments or extreme temperature fluctuations over time. With these advantages in mind, if you are looking for a reliable material that can meet your application’s demands, then 904L stainless steel could be just what you need!

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