What is 1.4306 Stainless Steel?

1.4306 stainless steel, commonly known as 304L or UNS S30403, is the low-carbon version of the widely used 304 austenitic stainless steel. Its reduced carbon content provides excellent resistance to intergranular corrosion after welding, making it the preferred choice for heavy welded fabrications such as tanks, pipelines, and structural components in chemical, food processing, and architectural industries.

 

This low-carbon grade is standardized under all major international systems.

Standard	Equivalent Grade
EN (Europe)	1.4306
ASTM/AISI (USA)	304L, UNS S30403
JIS (Japan)	SUS304L
KS (Korea)	STS304L

The low carbon content is the key differentiating factor.

Element	C	Si	Mn	P	S	Cr	Ni
Content (%)	≤ 0.03	≤ 1.0	≤ 2.0	≤ 0.045	≤ 0.03	17.5 - 19.5	8.0 - 10.5

It maintains excellent ductility and good strength, similar to standard 304.

Property	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HB)
Typical Value	≥ 180 MPa	490 - 690 MPa	≥ 40%	≤ 215

 

Key Characteristics and Applications of 1.4306 / 304L

Excellent Weldability without Sensitization: The low carbon content minimizes chromium carbide formation in the heat-affected zone during welding, preventing intergranular corrosion without the need for post-weld heat treatment.

Good General Corrosion Resistance: Performs well in a wide range of atmospheric, chemical, and food industry environments, similar to standard 304.

Superior Formability and Ductility: Retains the high ductility and formability characteristic of austenitic stainless steels, suitable for deep drawing, bending, and spinning.

 

Primary Applications:

Welded Fabrications: Large storage tanks, pressure vessels, and process piping systems.

Food & Beverage Equipment: Welded vats, fermentation tanks, and conveyor systems where sanitation is critical.

Architectural & Structural: Welded façades, railings, and structures in corrosive atmospheres.

Heat Exchangers: Tubing and plates in applications where extensive welding is required.

 

What is the main difference between 304L (1.4306) and 304 (1.4301)?
The primary difference is the carbon content. 304L has a maximum carbon content of 0.03%, while 304 allows up to 0.07%. This makes 304L significantly more resistant to intergranular corrosion after welding or high-temperature exposure. 304L is the preferred choice for welded components that cannot be post-weld annealed, while 304 is often used for lightly welded or non-welded applications.

 

Can 304L be used in high-temperature applications?
While 304L can be used at elevated temperatures, its low carbon content means it does not have the same high-temperature strength as grades like 304H or 321. For continuous service above 425°C where creep strength is important, a higher carbon grade like 304H (1.4948) is recommended. 304L is suitable for intermittent high-temperature exposure where corrosion resistance is the primary concern.

Looking for a Reliable Supplier of 1.4306 / 304L Stainless Steel?
GNEE Steel supplies versatile 304L (1.4306) stainless steel in all standard forms-plate, sheet, coil, pipe, and bar-along with comprehensive processing services. We ensure material quality with full certification and support both stock and custom orders. If you have any requirements, please feel free to contact us.