Stainless Steel 309, 310, and 310S are high-temperature chromium–nickel austenitic stainless steels.
To begin with, they are specifically developed for exceptional oxidation resistance and mechanical stability in continuous high-heat environments.
Furthermore, these grades exhibit superior resistance to scaling, thermal fatigue, and carburizing atmospheres.
When selecting the right grade for your high-temperature application, consider the following:First, SS 309 is suitable for elevated-temperature service with good oxidation resistance.
Next, SS 310 offers excellent performance up to extreme temperatures — making it ideal for the most demanding heat conditions.
Finally, SS 310S features low carbon content, providing improved weldability and resistance to carbide precipitation during fabrication.
As a result, these grades are commonly used in furnace components, radiant tubes, kiln linings, and burners.
Moreover, they are also trusted for heat treatment equipment and thermal processing systems.
Equally important, SS 309/310/310S are recognized for long-term exposure to severe heat and cyclic temperature conditions.
Consequently, their combination of high-temperature strength, oxidation resistance, and fabrication reliability makes them indispensable for industrial furnace and heating applications.
Need expert guidance on selecting the right high-temperature grade for your application?Contact our technical team today — we’ll help you choose between 309, 310, or 310S based on your operating temperatures and fabrication requirements, and provide a competitive quote tailored to your needs.
Other Types of Stainless Steel 309 / 310 / 310S Bars
309/310/310S STAINLESS STEEL ROUND BAR EQUIVALENT GRADES
STANDARD
UNS
WNR.
AFNOR
EN
JIS
BS
GOST
SS 309
S30900
1.4828
–
–
SUS 309
–
–
SS 310
S31000
1.4841 / 1.4307
–
X15CrNi25-20
SUS 310
310S24
20Ch25N20S2
SS 310S
S31008
1.4845
–
–
SUS 310S
–
20Ch23N18
SPECIFICATION OF STAINLESS STEEL 309/310/310S ROUND BAR
Stainless Steel Round Bar Specification
ASTM A276 / A479, ASME SA276 / A479
Dimension Standard
EN, DIN, JIS, ASTM, BS, ASME, AISI
Size
14 mm – 300 mm
Thickness
50 mm to 6000 mm Long
Length
1 to 6 Meters, Custom Cut Length
Form
Round, Square, Hex (A/F), Rectangle, Billet, Ingot, Forging Etc.
CHEMICAL COMPOSITION OF STAINLESS STEEL 309/310/310S ROUND BAR
Grade
C%
Mn%
Si%
P%
S%
Cr%
Ni%
Fe%
309
0.20 max
2.0 max
1.0 max
0.045 max
0.03 max
22.0 – 24.0
12.0 – 15.0
Balance
310
0.25 max
2.0 max
1.50 max
0.045 max
0.03 max
24.0 – 26.0
8.0 – 12.0
Balance
310S
0.08 max
2.0 max
1.50 max
0.045 max
0.03 max
24.0 – 26.0
19.0 – 22.0
Balance
MECHANICAL PROPERTIES OF STAINLESS STEEL 309/310/310S ROUND BAR
Grade
Tensile Strength (ksi)
Yield Strength 0.2% (ksi)
Elongation (%)
Hardness (Brinell) MAX
309
40 min
30 min
40
217
310
75 (515 MPa)
30 (205 MPa)
40
–
310S
75 (515 MPa)
30 (205 MPa)
40
–
PHYSICAL PROPERTIES OF 309/310/310S STAINLESS STEEL ROUND BAR
Grade
Density lb/in³
Thermal Conductivity (BTU/h ft. °F)
Electrical Resistivity (in x 10⁶)
Modulus of Elasticity (psi x 10⁶)
Coefficient of Thermal Expansion (in/in)/°F x 10⁶
Specific Heat (BTU/lb/°F)
Melting Range (°F)
309
0.285 at 68°F
9.0 at 32–212°F
30.7 at 68°F
28.5
8.28 at 32–212°F
0.1200 at 68–212°F
2500 – 2590
GENERAL PHYSICAL DATA OF SS 309/310/310S
Density
Melting Point
8.0 g/cm³
1454°C (2650°F)
💡 Practical Difference in Use
Use Stainless Steel 309 Round Bars when: high oxidation resistance and moderate heat strength are required for components exposed to intermittent or continuous elevated temperatures in furnaces, kilns, and thermal equipment.
→ Example: furnace fixtures, heat shields, burner parts, duct supports, and thermal processing hardware.
Use Stainless Steel 310 Round Bars when: very high temperature resistance, excellent scaling protection, and superior strength are required for continuous service in extreme heat environments.
→ Example: radiant tubes, combustion chambers, furnace rollers, heat exchanger rods, and petrochemical heaters.
Use Stainless Steel 310S Round Bars when: improved weldability, resistance to carbide precipitation, and long-term stability at elevated temperatures are critical for fabricated or welded high-heat assemblies.
→ Example: welded furnace frames, thermal processing supports, incinerator components, high-temperature ducts, and fabricated heater parts.
To begin with, Stainless Steel 309, 310, and 310S round bars are widely used in high-temperature and oxidation-resistant applications.
Furthermore, they are preferred where mechanical stability, corrosion resistance, and thermal endurance are essential for long-term reliable operation.
Heat Treatment & Furnace Equipment: Fixtures, radiant tubes, trays, rollers, and support rods.
Power & Energy Systems: Boiler internals, heat exchanger tie rods, exhaust supports, and thermal shields.
When to Choose Stainless Steel 309 vs. 310 vs. 310S Round Bars?
First and foremost, the selection mainly depends on operating temperature range, oxidation resistance requirements, fabrication method, and long-term thermal stability.
Consequently, choosing the right grade ensures optimal performance and extended service life in high-heat environments.
Choose SS 309 Round Bars when:
Moderate to high temperature resistance is required
Good oxidation and scaling resistance is needed
Components face intermittent thermal cycling
Used in furnace parts, ducting supports, heat shields
Cost-effective high-temperature alloy is preferred
Mechanical strength at elevated temperature is sufficient
Choose SS 310 Round Bars when:
Continuous exposure to extreme temperatures is expected
Maximum oxidation and carburization resistance is required
High mechanical strength at elevated temperature is critical
Used in radiant tubes, furnace rollers, combustion chambers
Long service life in aggressive thermal environments is needed
Higher alloy content is acceptable
Choose SS 310S Round Bars when:
Excellent weldability and fabrication are required
Reduced risk of carbide precipitation is important
Thermal cycling and welded assemblies are involved
Used in fabricated furnace frames and heat equipment
Stable performance at high temperature is essential
Low carbon composition is beneficial
Industries That Use Stainless Steel 309 / 310 / 310S Round Bars
To begin with, these grades are widely used in industries where high-temperature strength, oxidation resistance, and long operational life are critical.
Moreover, their versatility makes them suitable for applications ranging from heat treatment equipment to extreme high-temperature processing.
Furnace & Heat Treatment Industry
Primary usage: thermal processing environments.
Uses
Radiant tubes, fixtures, trays, rollers, support rods.
Why SS 310?
Excellent strength and oxidation resistance at extreme temperatures.
Petrochemical & Refining
Primary usage: high-heat and corrosive process equipment.
Excellent weldability, thermal stability, and resistance to carbide precipitation in sensitive environments.
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Looking for high-quality Stainless Steel 309 / 310 / 310S Round Bars & Rods? Fully compliant with ASTM A276, A479 and ASME SA276, SA479. Get in touch with us today.
