Lincoln Electric SuperGlaze® 4043 is a copper-free aluminum solid MIG wire classified per AWS A5.10/A5.10M: ER4043. Containing 4.5–6.0 % silicon, SuperGlaze 4043 has a lower melting point and greater fluidity than 5XXX series filler alloys, producing a wider, flatter bead that flows readily into joint grooves. This silicon-based chemistry gives ER4043 the lowest sensitivity to hot cracking of any aluminum filler alloy — a critical attribute when welding crack-susceptible 6XXX series base metals (6061, 6063, 6082) that would otherwise crack with pure 1XXX or 5XXX fillers. SuperGlaze 4043 also tolerates elevated service temperatures above 65 °C (150 °F), making it the recommended choice for automotive frame components, heat exchanger tubing, and bicycle frames that operate in warm environments. The DCEP polarity and 100 % Argon shielding gas requirement are standard for all aluminum MIG welding.
| Parameter | Value |
|---|---|
| AWS Classification | ER4043 (AWS A5.10/A5.10M: 2012 / ASME SFA-A5.10) |
| CWB Classification | CWB/CSA W48 ER4043 |
| Available Diameters | 0.030 in (0.8 mm), 0.035 in (0.9 mm), 3/64 in (1.2 mm) |
| Shielding Gas | 100 % Argon; 30–50 CFH (14–24 L/min) |
| Polarity | DCEP (DC electrode positive) |
| Welding Positions | All positions (1G, 2G, 3G, 4G) |
| Tensile Strength (minimum) | 29 ksi (200 MPa) |
| Silicon (Si) | 4.5–6.0 % |
| Aluminum (Al) | Remainder (balance) |
| Iron (Fe) | 0.80 % maximum |
| Copper (Cu) | 0.30 % maximum |
| Melting Range | 573–625 °C (1,063–1,157 °F) |
| Base Alloy Compatibility | 1XXX, 3XXX, 6XXX series, and most aluminum casting alloys |
SuperGlaze 4043's ER4043 chemistry per AWS A5.10 makes it the preferred aluminum MIG wire for 6XXX series heat-treatable alloys and casting repair:
- Automotive and transportation — frame rails, drive shafts, engine mounts, and suspension components on 6061-T6 and 6063-T5 extrusions; automotive manufacturers specify 4043 for crack-sensitive 6XXX base metal combinations
- Bicycle and sporting equipment frames — 6061 tube-to-tube TIG and MIG joints where hot crack resistance and smooth bead finish are required
- Heat exchangers and HVAC systems — tube-to-header welds and manifold assemblies in elevated-temperature service above 65 °C where 5356 is not recommended
- Marine hardware and marine structures — 6061 extrusion fabrication, boat railings, and marine architectural components
- Aluminum casting repair — foundry casting repair on 356, 380, and 413 casting alloys where 4043's silicon content matches the silicon-rich casting chemistry
- General 6XXX fabrication — window frames, ladder rails, architectural panels, and consumer goods manufactured from 6061 or 6063 aluminum
ER4043's 4.5–6.0 % silicon content serves two functions: it reduces the solidification temperature range (narrowing the "mushy zone" where hot cracking nucleates) and it increases weld metal fluidity for better groove filling and toe wash-in. When 6XXX base metals are welded with silicon-free or low-silicon fillers, the base metal silicon diffuses into the weld pool and creates a crack-susceptible alloy composition. ER4043 pre-saturates the pool with silicon, preventing this crack-sensitive intermediate composition.
The 100 % Argon shielding gas is mandatory for aluminum MIG welding. Argon provides stable cathodic cleaning that removes the aluminum oxide layer (Al₂O₃) as the arc sweeps across the base metal, ensuring fusion without oxide inclusion. Gas flow rates of 30–50 CFH (14–24 L/min) are typically required; higher flow rates may be needed in drafty conditions. Per Lincoln Electric SuperGlaze 4043 product data, do not use CO₂ or Ar/CO₂ blends with aluminum wire — these gases will produce an unstable arc and excessive oxidation. ER4043 welds are not suitable for anodizing (ER5356 is recommended if anodizing is required).
| Diameter | Polarity | Gas | CTWD | WFS (in/min) | Voltage (V) | Current (A) |
|---|---|---|---|---|---|---|
| 0.035 in (0.9 mm) | DCEP | 100% Ar | 1/2–5/8 in | 585 (recommended) | 14–24 | 170 |
| 3/64 in (1.2 mm) | DCEP | 100% Ar | 1/2–5/8 in | 350 (recommended) | 14–24 | 195 |
SuperGlaze 4043 is classified as ER4043 per AWS A5.10/A5.10M: 2012 and ASME SFA-A5.10. The designation means: E = electrode, R = rod (usable as TIG filler), 4043 = the alloy composition number (Al-Si alloy with 4.5–6.0 % Si). It is also approved to CWB/CSA W48 ER4043 for Canadian Welding Bureau requirements.
100 % Argon is required. Aluminum MIG welding relies on the cathodic etching action of pure Argon to break up and remove the aluminum oxide (Al₂O₃) layer during welding. Gas flow should be set at 30–50 CFH (14–24 L/min). Do not use CO₂, Ar/CO₂ blends, or Ar/He blends for standard MIG aluminum welding — these gases compromise arc stability and promote oxidation.
Use ER4043 (SuperGlaze 4043) when welding: 6XXX series base metals (6061, 6063, 6082) where hot crack resistance is critical; casting alloys (356, 380); applications at elevated temperatures > 65 °C; or when a smoother, flatter bead with lower spatter is desired. Use ER5356 when: welding 5XXX series base metals; the part will be anodized (4043 welds turn dark gray after anodizing); or higher weld deposit tensile strength (> 40 ksi) is needed for structural aluminum applications.
Yes — the "ER" in ER4043 means the wire qualifies as both a MIG electrode and a TIG filler rod. SuperGlaze 4043 cut lengths can be used as filler rod in GTAW (TIG) applications on 6XXX and casting alloys. For TIG welding aluminum, use AC power with 100 % Argon shielding gas, the same alloy selection criteria apply.
ER4043's high silicon content causes the weld bead to appear dark gray to black after anodizing — the silicon does not anodize the same color as the surrounding aluminum. If the finished part will be anodized for appearance (architectural components, consumer products), use ER5356 which produces a silver finish closer to the base metal color after anodizing. For functional anodizing (corrosion protection without color matching), ER4043 is acceptable.
Browse the full welding wire collection, or see related Lincoln Electric wire products: SuperArc L-56 for carbon steel MIG, or Harris ER70S-6 for mild steel GMAW.