Lincoln Electric Blue Max ER308LSi is the standard austenitic stainless steel MIG wire for welding 304, 304L, and 308-series stainless steel. Classified AWS A5.9/A5.9M ER308LSi, this 0.035 in (0.9 mm) wire on a 33 lb spool (ED037250) provides higher silicon content (0.65–1.00% Si) than standard ER308L, improving wetting, fluidity, and bead appearance in spray arc transfer applications. The low carbon content (≤ 0.03% C) prevents sensitization and intergranular corrosion in heat-affected zones on base metal up to 3/16 in thick. Blue Max ER308LSi is the most frequently specified stainless MIG wire for food service equipment, pharmaceutical vessels, and dairy processing systems. WeldingMart is an authorized Lincoln Electric distributor. See the full welding wire catalog.
| Property | Value |
|---|---|
| AWS Classification | ER308LSi per AWS A5.9/A5.9M |
| Lincoln Part Number | ED037250 |
| Wire Diameter | 0.035 in (0.9 mm) |
| Spool Weight | 33 lb (15 kg) |
| Carbon Content | ≤ 0.03% C (low carbon) |
| Silicon Content | 0.65–1.00% Si (high-Si variant) |
| Chromium Content | 19.5–22.0% Cr |
| Nickel Content | 9.0–11.0% Ni |
| 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 | ≥ 35% |
| Welding Process | GMAW (MIG), spray arc transfer |
| Conformances | AWS A5.9/A5.9M, ASME SFA-5.9 |
- Food service and dairy: Stainless steel tanks, conveyors, preparation surfaces, and mixing vessels in 304 or 304L stainless — ER308LSi's low carbon prevents sensitization critical for FDA/3-A Sanitary Standards compliance.
- Pharmaceutical manufacturing: Bioreactor vessels, piping, and clean room equipment in 304L stainless where weld corrosion resistance must meet ASME BPE standards.
- Chemical processing: Storage tanks, heat exchangers, and pressure vessels in 304 stainless for dilute acid, alkali, and salt solutions at ambient temperature.
- Architectural stainless: Building facades, railings, countertops, and decorative panels in 304 stainless where smooth bead appearance and color consistency after pickling are required.
- General industrial fabrication: Stainless exhaust systems, brackets, frames, and enclosures where 308-type corrosion resistance is specified.
- Automotive exhaust (OEM and aftermarket): 304 stainless exhaust headers and manifolds, though ER309LSi is preferred for 409-to-304 dissimilar transitions.
The "Si" suffix indicates higher silicon content (0.65–1.00% Si) versus standard ER308L (0.30–0.65% Si). Silicon acts as a surfactant in the weld puddle:
| Property | ER308L (standard) | ER308LSi (this product) |
|---|---|---|
| Silicon Content | 0.30–0.65% Si | 0.65–1.00% Si |
| Puddle Fluidity | Moderate | Higher — better wetting |
| Bead Appearance | Good | Excellent — smoother profile |
| Transfer Mode | Short arc or spray | Spray arc preferred |
| Best Gas | Tri-mix or 98/2 Ar/O₂ | Tri-mix or 98/2 Ar/O₂ |
| AWS Spec | AWS A5.9 ER308L | AWS A5.9 ER308LSi |
Use tri-mix (90% He / 7.5% Ar / 2.5% CO₂) for the smoothest spray arc on stainless. Alternatively, 98% Ar / 2% O₂ works well and is more widely available. Do not use pure CO₂ or standard C25 (Ar/CO₂) shielding — these gas blends cause excessive oxidation, carbon pickup, and loss of chromium in the stainless weld. Source: Lincoln Electric Blue Max Stainless MIG Wire.
Run on DCEP (electrode positive) with tri-mix or 98/2 Ar/O₂ shielding gas:
| Material Thickness | WFS (in/min) | Voltage (V) | Amperage | Shielding Gas |
|---|---|---|---|---|
| 12 gauge (0.104 in) | 270–330 | 23–25 | 120–155 A | 98/2 Ar/O₂, 25 CFH |
| 1/8 in (3.2 mm) | 330–410 | 25–27 | 150–190 A | 98/2 Ar/O₂, 28 CFH |
| 3/16 in (4.8 mm) | 400–480 | 26–28 | 180–225 A | Tri-mix, 30 CFH |
| 1/4 in (6.4 mm) | 460–540 | 27–29 | 210–260 A | Tri-mix, 35 CFH |
- What is the difference between ER308L and ER308LSi?
- ER308LSi has higher silicon (0.65–1.00%) than ER308L (0.30–0.65%), improving puddle fluidity and bead appearance in spray arc transfer. Both have the same low-carbon ≤ 0.03% C chemistry for sensitization resistance.
- What shielding gas should I use for stainless MIG welding with ER308LSi?
- Use tri-mix (90% He / 7.5% Ar / 2.5% CO₂) or 98/2 Ar/O₂. Never use C25 (75/25 Ar/CO₂) on stainless — excess CO₂ causes carbon pickup and chromium loss.
- Can ER308LSi be used to weld 316L stainless?
- It can be used in mildly corrosive environments, but for full chloride resistance of 316L, use ER316LSi which contains 2–3% molybdenum.
- What stainless steel grades is ER308LSi designed to weld?
- Designed for 304, 304L, 308, and 308L austenitic stainless steels. ASME Section IX and AWS D1.6 qualification supported.
- Does ER308LSi prevent sensitization in stainless heat-affected zones?
- Yes. Low carbon (≤ 0.03% C) minimizes chromium carbide precipitation in the HAZ, preserving corrosion resistance without post-weld annealing in most service applications.
Related products: Blue Max ER308LSi 0.045 in, 33 lb (ED037251) | Blue Max ER316LSi 0.035 in, 33 lb (ED037302) | All Welding Wire