100999 - CWI ER309LSi .030" Stainless MIG Wire - 2lb Spool

Premium ER309LSi Stainless Steel MIG Wire

The Central Wire ER309LSi is a high-quality stainless steel MIG welding wire designed for critical fabrication and repair tasks. This 0.030-inch diameter wire comes in a convenient 2-pound spool, making it ideal for smaller jobs, portable welding units, or spool guns. The "Si" in the classification denotes a higher silicon content than standard 309L wire. This addition significantly improves the wetting action of the molten weld pool, allowing the metal to flow more smoothly at the toes of the weld. The result is a flatter, more aesthetically pleasing bead with excellent wash-in, reducing the need for post-weld grinding.

This alloy is specifically engineered for joining dissimilar metals, such as welding 304 stainless steel to mild carbon steel. It is also frequently used for depositing buffer layers before cladding. The "L" designation indicates a low carbon content (0.03% maximum), which is crucial for preventing intergranular corrosion caused by carbide precipitation during the welding process. This ensures the weld maintains its corrosion-resistant properties even in harsh environments.

Central Wire Industries (CWI) is renowned for its strict quality control and precision manufacturing. This wire features a clean surface finish and consistent diameter, ensuring stable electrical conductivity and smooth feeding through your MIG gun liner. Whether you are working on automotive exhaust systems, general fabrication, or maintenance repairs involving mixed metals, this ER309LSi wire delivers professional, reliable results.

Key Technical Properties

• Classification: AWS A5.9 ER309LSi
• Tensile Strength: Typically 85,000 PSI (depending on gas/parameters)
• Elongation: ~35%
• Shielding Gas: Argon/CO2 blends or Argon/Helium/CO2 tri-mixes recommended