The “L” in 304L and 316L denotes a low-carbon variant. Standard 304 and 316 contain up to 0.08% carbon, while 304L and 316L contain a maximum of 0.03% carbon.
The lower carbon content reduces carbide precipitation at grain boundaries during welding, which in turn prevents inter-granular corrosion in the heat-affected zone. This makes the L-grades the preferred choice for welded fabrications, particularly in chemical, pharmaceutical, and food processing applications where weld integrity is critical.
Standard 304 and 316 offer slightly higher tensile strength and are suitable for non-welded or lightly welded applications where post-weld heat treatment is feasible. SSSS Group stocks both standard and L-grade variants in sheets, coils, plates, and pipes.

Duplex stainless steel is a family of grades that combines austenitic and ferritic phases in roughly equal proportions, giving it a unique balance of properties:

• Approximately twice the strength of standard austenitic grades like 304 or 316
• Excellent resistance to stress corrosion cracking
• Superior resistance to pitting and crevice corrosion in chloride environments
• Lower nickel content, offering a degree of price stability compared to nickel-heavy austenitics

Common duplex grades include Duplex 2205 (standard duplex) and Duplex 2507 (super-duplex). Typical applications include chemical processing plants, desalination equipment, offshore oil & gas structures, heat exchangers, pulp and paper, and marine environments. SSSS Group supplies duplex grades in sheets, plates, coils, pipes, flanges, and fittings