Lincoln Electric Blue Max ER309LSi (ED037293) is the complete family hub listing for the premier austenitic stainless MIG wire engineered for dissimilar metal welding and stainless overlay applications. Classified AWS A5.9/A5.9M ER309LSi, this wire is available in 0.030 in, 0.035 in, and 0.045 in diameters in 25 lb and 33 lb spool configurations and 500 lb Accu-Trak drum packages for high-volume operations. ER309LSi's elevated chromium (23–25% Cr) and nickel (12–14% Ni) content, combined with high silicon (0.65–1.00% Si) for improved wetting and low carbon (≤ 0.03% C) to resist sensitization, make it the industry's reference filler for joining 304 or 316 stainless steel to carbon and low-alloy steels. WeldingMart stocks the complete Blue Max 309LSi diameter lineup as an authorized Lincoln Electric distributor. Browse the full welding wire catalog for all available packages.
| Property | Value |
|---|---|
| AWS Classification | ER309LSi per AWS A5.9/A5.9M |
| Lincoln Product Family | Blue Max 309LSi (ED037291, ED037292, ED019296, ED023962, ED029770, ED029771) |
| Available Diameters | 0.030 in, 0.035 in, 0.045 in |
| Available Packages | 25 lb spool, 33 lb spool, 500 lb Accu-Trak drum |
| Carbon Content | ≤ 0.03% C |
| Silicon Content | 0.65–1.00% Si |
| Chromium Content | 23.0–25.0% Cr |
| Nickel Content | 12.0–14.0% Ni |
| Manganese Content | 1.0–2.5% Mn |
| Polarity | DCEP (electrode positive) |
| Shielding Gas | Tri-mix (90% He / 7.5% Ar / 2.5% CO₂) or 98% Ar / 2% O₂ |
| Tensile Strength (as-welded) | ≥ 515 MPa (75,000 psi) |
| Yield Strength (as-welded) | ≥ 310 MPa (45,000 psi) |
| Elongation | ≥ 30% |
| Welding Processes | GMAW (MIG), spray arc, pulsed MIG, short arc |
| Conformances | AWS A5.9/A5.9M, ASME SFA-5.9 |
- Dissimilar metal piping joints: The most common use — joining 304 or 316 stainless steel pipe to carbon steel flanges, fittings, and headers in chemical, petrochemical, and power generation plants.
- Stainless overlay cladding: Depositing a corrosion-resistant stainless layer on carbon steel vessel shells, tank interiors, and reactor beds exposed to acidic or saline environments.
- Exhaust system dissimilar transitions: Joining 409 or 439 ferritic stainless steel mufflers and heat shields to 304 austenitic stainless manifolds and intermediate pipes.
- Maintenance and repair: Field repair of worn or damaged stainless components mounted on carbon steel structures, where base metal chemistry may be unknown or mixed.
- Bridge and infrastructure stainless components: Welding 304 stainless architectural components (exposed railings, facings) to structural carbon steel subframes in public infrastructure projects.
- Cryogenic transition joints: Stainless cryogenic lines (LNG, liquid nitrogen) connecting to carbon steel support structures and manifolds.
| Diameter | Material Thickness Range | Transfer Mode | Lincoln Part Numbers |
|---|---|---|---|
| 0.030 in | 18 ga – 3/16 in | Short arc, pulsed MIG | ED023962 (25 lb) |
| 0.035 in | 14 ga – 1/4 in | Spray arc, pulsed MIG | ED037291 (33 lb), ED029770 (500 lb) |
| 0.045 in | 3/16 in – 1/2 in | Spray arc, pulsed MIG | ED037292 (33 lb), ED029771 (500 lb) |
For 0.035 in ER309LSi stainless cladding in the flat position, use spray arc transfer at 155–230 A with tri-mix shielding gas. For out-of-position work, switch to pulsed MIG. Source: Lincoln Electric Blue Max Stainless MIG Wire.
| Diameter | Material Thickness | WFS (in/min) | Voltage (V) | Amperage | Gas |
|---|---|---|---|---|---|
| 0.035 in | 1/8 in (3.2 mm) | 320–410 | 24–26 | 150–195 A | Tri-mix, 28 CFH |
| 0.035 in | 1/4 in (6.4 mm) | 420–520 | 26–28 | 200–255 A | Tri-mix, 35 CFH |
| 0.045 in | 3/16 in (4.8 mm) | 270–350 | 25–27 | 185–230 A | Tri-mix, 30 CFH |
| 0.045 in | 3/8 in (9.5 mm) | 380–460 | 27–29 | 240–300 A | Tri-mix, 40 CFH |
- What AWS classification is ER309LSi and what do L and Si mean?
- AWS A5.9/A5.9M ER309LSi: 'L' = low carbon (≤ 0.03% C, prevents sensitization); 'Si' = elevated silicon (0.65–1.00%, improves puddle flow). Together these make ER309LSi the top choice for dissimilar metal applications requiring low sensitization risk and good bead appearance.
- When do I use ER309LSi vs ER308LSi?
- ER308LSi: same-grade stainless joints (304-to-304). ER309LSi: stainless-to-carbon steel, stainless cladding on carbon steel, and 409-to-304 exhaust dissimilar transitions.
- Can I use ER309LSi to repair stainless steel exhaust systems?
- Yes — standard for 409-to-304 exhaust repairs. For same-grade 304-to-304 exhaust repair, ER308LSi is also acceptable.
- What minimum machine amperage is needed for ER309LSi 0.035 in spray arc?
- Approximately 150 A minimum for spray arc. Most 200 A MIG machines can achieve spray arc with 0.035 in ER309LSi in Ar/O₂ shielding gas.
- Is ER309LSi available in drum packaging for high-volume cladding operations?
- Yes — Lincoln Blue Max 309LSi ships in 500 lb Accu-Trak drums (ED029770 for 0.035 in; ED029771 for 0.045 in) for robotic cladding applications.
Related products: Blue Max ER309LSi 0.035 in, 33 lb (ED037291) | Blue Max ER316LSi 0.035 in, 33 lb (ED037302) | All Welding Wire