ThePipingMart Blog Grades 440B Stainless Steel (UNS S44003) – Composition, Properties and Uses

440B Stainless Steel (UNS S44003) – Composition, Properties and Uses

440B Stainless Steel

Have you ever heard of 440B stainless steel? This particular steel alloy is incredibly versatile and has many uses in industry. It’s an excellent choice for applications that require strength and corrosion resistance. Let’s take a closer look at what sets this alloy apart, its composition and mechanical properties, physical properties, and some of the common applications.


The chemical composition of 440B ss consists of 17–19% chromium, 0.75–1% carbon, 0.7–1% molybdenum, 1.25–2% nickel, 0.5–1% manganese, up to 1% silicon, up to 0.04% phosphorus with traces of sulfur, nitrogen and titanium.

Element Content (%)
Iron, Fe 80
Chromium, Cr 16.0-18.0
Manganese, Mn 1.0
Silicon, Si 1.0
Carbon, C 0.75-0.95
Molybdenum, Mo 0.75
Phosphorous, P 0.040
Sulfur, S 0.030

Mechanical Properties

SS 440B has excellent heat-treating properties and can be hardened to 56 HRC or higher, depending on the application it is used for. It also possesses good wear resistance and ductility when properly heat-treated, which makes it suitable for use in applications such as turbine blades and medical instruments where high levels of strength are required, but flexibility must be maintained too.

Properties Metric Imperial
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30

Physical Properties

UNS S44003 has a melting point range between 1480-1520°C (2700-2790°F). Its tensile strength ranges between 860-1150 MPa (125-168 ksi), while its yield strength typically falls between 400-850 MPa (58-124 ksi). Its elongation after fracture amounts to 15%.

Properties Metric Imperial
Density 7.74 g/cm3 0.280 lb/in³
Melting point 1482°C 2700°F

Thermal Properties

Properties Metric Imperial
Thermal conductivity (for stainless 410A0) 24.2 W/mK 168 BTU in/hr.ft².°F


DIN 1.4112 QQ S763 FED QQ-S-763 MIL SPEC MIL-S-862
SAE J405 (51440B) SAE 51440B ASTM A580


Due to its high hardness levels, corrosion resistance capabilities and good wear properties, this type of steel is often used in cutting tools like chisels or surgical instruments where there is a need for sharpness as well as resistance against rusting or pitting caused by contact with harsher substances or liquids over time. It is also often employed in heavy-duty machinery parts that are exposed to intense pressure or heat, like turbine blades, as well as in industrial valves or locks, due to its resistance against abrasion from repeated use or changes in temperature or humidity levels over time.


440B stainless steel is an incredibly versatile material that can be used for a wide variety of applications ranging from medical tools to machine parts thanks to its excellent mechanical properties, such as hardness levels and wear resistance combined with good corrosion protection capabilities, all within an affordable price range – making it an excellent option for those looking for a reliable material that won’t break the bank! With so much going for it – why not give this alloy a try today?

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