100999 - ER309LSi .035 Stainless MIG Wire 33lb Spool

Premium ER309LSi Stainless Steel MIG Wire for Industrial Fabrication

The Central Wire ER309LSi .035" Stainless Steel MIG Wire is a high-performance consumable designed for demanding industrial applications requiring the joining of dissimilar metals. Packaged on a standard 33lb spool, this wire is engineered to meet the rigorous standards of the AWS A5.9 specification. The "LSi" designation indicates a modification to the standard 309L analysis; it features a higher silicon content (typically 0.65-1.00%) which significantly enhances the wetting characteristics of the molten weld pool. This results in a smoother bead profile, improved tie-in at the toes of the weld, and greater arc stability compared to standard 309L wires.

This wire is the industry standard for welding Type 309 stainless steel, but its primary utility in the MRO and fabrication sectors lies in its ability to join carbon steels or low-alloy steels to stainless steels (such as 304 or 316). It is also extensively used for depositing buffer layers on carbon steel prior to the application of 308 or 316 cladding. The low carbon content (maximum 0.03%) minimizes carbide precipitation during the welding process, thereby preserving the corrosion resistance of the weldment and protecting against intergranular corrosion.

Central Wire's precision layer winding technology ensures that the wire feeds smoothly through MIG gun liners and drive rolls, reducing downtime caused by bird-nesting or feed interruptions. This product is compatible with various shielding gas mixtures, including Argon/CO2 (98/2) and Argon/Oxygen blends, making it versatile for different shop setups. Whether used for petrochemical equipment, heat exchangers, or general structural repairs involving mixed metallurgy, this ER309LSi wire delivers consistent, high-quality results.