439 Stainless Steel Alloy

UNS: S43900
EN-DIN: 1.4510

439 Stainless Steel Strip, Coil & Sheet

  • ASTM A240

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439 Stainless Steel Alloy Description:

439 Oxidation resistance and corrosion resistance is superior to Type 409 in areas where temperatures may exceed the oxidation limit of Type 409 or where aqueous corrosion resistance, particularly to chlorides, is needed.  

Type 439 stainless steel is a Titanium-stabilized 17% to 18% Chromium ferritic stainless steel with improved weldability. Due to its high Chromium content, corrosion resistance is much higher compared to type 409, in a variety of oxidizing environments, from fresh water to boiling acids.

Stainless steel 439 does not require annealing after welding to restore ductility or provide intergranular corrosion resistance. This type of steel is often used in applications that require high formability, such as the automotive industry, providing good oxidation and corrosion resistance for exhaust system components including mufflers, pipes, and catalytic converters, as well as residential furnace primary heat exchanger and sugar industry applications as examples.


439 Stainless Steel Alloy Uses & Applications:

Applications include tubular manifolds and other exhaust systems with difficult to form exhaust components.

Note that 439 stainless steel can be work-hardened slightly to increase tensile strength and is not subject to Chloride stress corrosion cracking. It is often used where high thermal conductivity is required.

  • Good general corrosion resistance particularly in fresh waters and mildly oxidizing environments
  • Excellent welding properties
  • High thermal conductivity coefficient
  • Low thermal expansion coefficient
  • Reflective color compatibility
  • Good continuous & cyclic oxidation resistance
  • Long-term cost advantages

Nominal Composition


Physical Properties

At 70°FAt 20°C
Density0.278 lb./in³7685 kg/cm³
Modulus of Elasticity (E)28.4 x 10³ ksi193 x 10³MPa
Electrical Resistivity24.0 μ ohm.in60.0 μ ohm.cm
Typical Room Temperature Mechanical Properties

Typical Mechanical Properties

Typical mechanical properties are based on AK source, ASTM A240.

ConditionTensile Strength Min (UTS)0.2% YS MinElongation% in 2” Min (50.8 mm)Hardness Rockwell
Annealed66 ksi (455 MPa)43 ksi (296 MPa)32%74 HRBW
Limitation of Liability and Disclaimer of Warranty:
  • The content in these data sheets is provided primarily by third-party melting mills and is provided for reference only. It is not intended for engineering or design.
  • Applications may be discussed, however, Combined Metals Company, LLC, does not recommend or endorse any material for any particular end use or application.
  • The data included in this data sheet are typical values and may vary.
  • Combined Metals Company, LLC, makes no representations or warranties, express or implied, as to the accuracy, completeness, condition, suitability, performance, fitness for a particular purpose, or merchantability of any information contained in any data sheet.

In no event will Combined Metals Company, LLC, be liable for any damages whatsoever arising from the use of the information included in the data sheets.

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