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

Chemical Composition of 309/309S Stainless Steel

Elements C Mn Si P S Ni Cr
309S ≤0.08 ≤2.00 ≤1.00 ≤0.045 ≤0.03 12.0-15.0 22.0-24.0
Elements C Si Mn P S Cr Ni
309 Min - - - - - 22 12
Max 0.2 1 2 0.045 0.03 24 15

Mechanical Properties of 309/309S Stainless Steel

Ultimate Tensile Strength /Mpa 0.2% Yield Strength /Mpa Elongation % Elongation at break
≥515 ≥205 ≥40 ≤50


Types 309S Stainless Steel can be roll formed, stamped, and drawn readily. In-process annealing is usually required to reduce hardness and increase ductility.

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

Popular Finish Options

A comprehensive collection of finishes is also available from QINGHE STEEL when purchasing stainless steel plate. Popular finish options include:

  • Also cold-rolled, the 2D finish has a matte surface with low reflectivity.
  • HR / No.1 . This hot-rolled finish has a scaled appearance and so is ideal where the final aesthetic is not an important concern.
  • BA / 2R. Cold rolled and annealed in a controlled atmosphere to retain a highly reflective finish. This highly-reflective finish is achieved by annealing the alloy in a carefully controlled atmosphere.
  • Smooth finish, reflective grey sheen. Most widely used surface finish. The most popular surface finish, 2B offers a smooth appearance with a grey, reflective sheen.

What Stainless Steel Grades We Have!

Qinghe Steel is a full line supplier and processer of stainless steel coil, sheet, plate, bar, and strip products. We stock many grades of stainless steel, including 300 and 400 series stainless, annealed and in various tempers and high temperature grades, for shipments worldwide. View our steel center here

Qinghe Steel stocks a wide range of stainless steel sizes for your specific project needs. We offer quick delivery throughout the world. Contact us today to discuss stainless steel for your project needs.


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.