309 309s Stainless Steel Supply


309/309S Stainless Steel is austenitic chromium-nickel stainless steel that is often used for higher temperature applications. Due to its high chromium and nickel content, 309/309S Stainless Steel is highly corrosion resistant, has outstanding resistance to oxidation, and excellent heat resistance while providing good strength at room and elevated temperatures. The significant difference between 309 and 309S is the carbon content. 309/309S Stainless Steel has a much less carbon composition which minimizes carbide precipitation and improves weldability. 309/309S is the ease of fabrication. It is often used in furnace equipment, annealing boxes, the rmowells, and other high-temperature applications.


  • ASTM/ASME: 309S/UNS S30908
  • DIN: 4833
  • GB:0Cr23Ni13
  • JIS:SUS309S

309/309S Stainless Steel Properties

Corrosion Resistance: 309/309S stainless steel has excellent corrosion resistance in high-temperature environments. It can withstand exposure to water, chemicals, and other corrosive substances without corroding or rusting.

Strength: 309/309S stainless steel has high tensile strength and can withstand heavy loads without bending or breaking. It has a minimum tensile strength of 515 MPa and a minimum yield strength of 205 MPa.

Ductility: 309/309S stainless steel has good ductility, which means that it can be easily formed and shaped without cracking or breaking. This property makes it ideal for applications that require complex shapes or designs.

Weldability: 309/309S stainless steel is easily weldable, making it an excellent choice for applications that require welding. It can be welded using common welding techniques, such as TIG, MIG, and resistance welding.

Magnetic Properties: 309/309S stainless steel is non-magnetic, which makes it suitable for applications that require non-magnetic properties.

Heat Resistance: 309/309S stainless steel has excellent heat resistance and can withstand high temperatures without losing its strength or corrosion resistance. It can withstand temperatures up to 1093°C (2000°F) without undergoing any significant change in its properties.

Chemical Composition of 309/309S Stainless Steel

309 ElementsCSiMnPSCrNi
Max0.2120.0450.0322 - 2412 - 15

Mechanical Properties of 309/309S Stainless Steel

Ultimate Tensile Strength /Mpa0.2% Yield Strength /MpaElongation %Elongation at break

Applications of 309/309S Stainless Steel

309/309S Stainless Steel is used exclusively for their high-temperature oxidation resistance, excellent high-temperature strength, along with their resistance to creep deformation and environmental attack. Some examples include, but are not limited to:

  • Aircraft and jet engine parts
  • Furnaces — burners, doors, fans, piping and recuperators
  • Fluidized Bed Furnaces — grids, piping, wind boxes
  • Paper Mill Equipment
  • Petroleum Refining — catalytic recovery systems, recuperators
  • Power Generation — pulverized coal burners, tube hangers
  • Thermal Processing — annealing covers and boxes, burners grids, doors, fans, lead pans and neutral salt pots, muffles and retorts, recuperators, walking beams
  • Waste Treatment — incinerators, rotary kilns and calciners

Read More:

Comparing Martensitic Stainless: 309 vs 310 Stainless Steel Grades

Spotting the Key Differences: 309 and 316 Stainless Compared

What Is The Difference : Grade 304 Vs Grade 309?


What is the difference between 304 and 309s stainless steel?

The stainless steel 309/309S Stainless Steel is austenitic and resistant to heat. 309/309S Stainless Steel has a little advantage over 304 stainless steel in terms of general corrosion resistance at high temperatures thanks to its 23 percent chromium content, or around 5 percent higher than 304 stainless steel.

Is 309 stainless steel magnetic?

Whereas the vast majority of stainless steels are magnetic, all types of austenitic stainless steels are non-magnetic.

The magnet test is NOT a correct way to verify stainless steel.

All stainless steel is magnetic except austenitic stainless steel which is actually 300 series stainless such as 304 and 316. However, 300 series stainless is non-magnetic only after it is freshly formed.  Initially the cold work causes the stainless to pick up foreign particles such as free iron. Then at some spots the metallic crystal structure changes from austenite to martensite. 400 series stainless (ie. martensitic stainless steel) is magnetic. Stainless steel containing more nickel (310 and 316 grades) is more likely to remain non-magnetic after cold work.

Does 309 stainless steel rust?

The alloy is prone to intergranular corrosion after long term exposure at high temperatures. However, due to its high chromium content (23%), Alloy 309 is more corrosion resistant than most heat resistant alloys.

what is 309 stainless steel used for?

If you want to do spot check of SS, just take a random piece from the raw material and do a spark test. Run a grinder on it, if the sparks are reddish orange, thin and don't fly much it's SS304. If the sparks are yellow, thick and fly lot further it is SS 202.