Lincoln Electric Blue Max ER308LSi in 0.030 in (0.8 mm) diameter on a 33 lb spool (ED037252) is the choice for MIG welding thin-gauge stainless steel sheet and light structural sections where heat input control and arc precision are critical. Classified AWS A5.9/A5.9M ER308LSi, this fine-diameter wire operates at lower amperages than 0.035 in or 0.045 in variants, enabling welding of 22-gauge through 10-gauge (0.030–0.134 in) 304 and 304L stainless steel. The high silicon content (0.65–1.00% Si) maintains excellent puddle fluidity and bead wetting at lower current, reducing the risk of cold lap and incomplete fusion on thin stainless. Low carbon (≤ 0.03%) ensures intergranular corrosion resistance in the heat-affected zone. WeldingMart stocks this product as an authorized Lincoln Electric distributor. See the complete welding wire catalog.
| Property | Value |
|---|---|
| AWS Classification | ER308LSi per AWS A5.9/A5.9M |
| Lincoln Part Number | ED037252 |
| Wire Diameter | 0.030 in (0.8 mm) |
| Spool Weight | 33 lb (15 kg) |
| Carbon Content | ≤ 0.03% C |
| Silicon Content | 0.65–1.00% Si |
| 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), short arc, pulsed MIG |
| Conformances | AWS A5.9/A5.9M, ASME SFA-5.9 |
- Food service equipment manufacturing: Thin stainless preparation tables, sinks, and shelving units from 18–22 gauge 304 stainless steel — 0.030 in wire reduces warping risk versus larger diameters.
- Pharmaceutical clean room components: Stainless steel trays, racks, and fixtures in 304L where heat input must be minimized to avoid distortion of precision-machined surfaces.
- Automotive exhaust systems: Thin-wall 304 stainless tubing (16–18 gauge) for performance exhaust headers and pipes — fine wire enables proper fusion on thin tubing walls.
- Architectural and decorative stainless: Thin sheet facades, elevator panels, signage, and trim components where excellent bead cosmetics on visible surfaces are required.
- Chemical instrument enclosures: Thin stainless analyzer housings, laboratory equipment, and sampling system components in 304L.
- HVAC stainless ductwork: Light-gauge 304 stainless duct systems and fume hoods in laboratory and industrial settings.
At 0.030 in, ER308LSi typically runs in short arc (GMAW-S) or pulsed MIG (GMAW-P) transfer mode. Spray arc is technically possible above ~140 A but is rarely used on thin stainless:
| Material Gauge | Transfer Mode | Amperage Range | Advantage |
|---|---|---|---|
| 18–22 gauge (0.048–0.030 in) | Short arc GMAW-S | 60–110 A | Minimum heat input, all positions |
| 14–18 gauge (0.075–0.048 in) | Pulsed MIG GMAW-P | 80–150 A average | Spray quality, out-of-position |
| 10–14 gauge (0.134–0.075 in) | Pulsed or short arc | 100–160 A | Good fusion control on vertical stainless |
For thin stainless, use a stringer bead (no weaving) to minimize heat input. Maintain consistent travel speed. Tack weld at close intervals (1–2 in) to control distortion. Argon backing on the root side of single-sided butt welds reduces sugaring (oxidized root bead). Source: Lincoln Electric Blue Max Stainless MIG Wire.
| Material Gauge / Thickness | WFS (in/min) | Voltage (V) | Amperage | Gas / Flow |
|---|---|---|---|---|
| 22 ga (0.030 in) | 150–200 | 16–18 | 55–80 A | 98/2 Ar/O₂, 20 CFH |
| 18 ga (0.048 in) | 200–260 | 18–20 | 75–110 A | 98/2 Ar/O₂, 22 CFH |
| 14 ga (0.075 in) | 260–330 | 20–22 | 105–145 A | Tri-mix, 25 CFH |
| 3/16 in (4.8 mm) | 320–400 | 22–24 | 140–185 A | Tri-mix, 28 CFH |
- When should I use 0.030 in ER308LSi instead of 0.035 in?
- Use 0.030 in for stainless thinner than 14 gauge (0.075 in), especially 18–22 gauge, where burn-through and distortion control are priorities. For 12 gauge and thicker, 0.035 in or 0.045 in is more productive.
- How do I prevent stainless steel from warping during thin sheet MIG welding?
- Use smallest effective wire, fast travel speed, low voltage, backstep welding, and copper/steel backing bars. Stainless has higher thermal expansion than carbon steel and warps more easily.
- What causes the root bead to turn black on stainless MIG welds (sugaring)?
- Sugaring is chromium oxidation from air exposure at high temperature. Prevent with argon back-purging. Remove any sugaring before service in corrosion-critical applications.
- Is 0.030 in ER308LSi compatible with standard MIG machines?
- Yes — most MIG machines covering 55–185 A are suitable. Ensure drive rolls and contact tips are sized for 0.030 in wire.
- Can I use ER308LSi for vertical stainless MIG welding?
- Yes, using short arc or pulsed MIG transfer. Avoid conventional spray arc out-of-position. Pulsed MIG with 0.030 in ER308LSi excels on thin to medium vertical stainless welds.
Related products: Blue Max ER308LSi 0.035 in, 33 lb (ED037250) | Blue Max ER309LSi 0.035 in, 33 lb (ED037291) | All Welding Wire