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How Many Amps Do You Need to Stick Weld Aluminum?
Using the wrong amperage on aluminum causes burn-through, weak joints, or failed starts.
Stick welding aluminum requires high amperage—usually 150 to 300 amps depending on electrode and material thickness.
Let’s break down the current you really need for aluminum—and why this process isn’t beginner-friendly.
How many amps to stick weld aluminum?
Low amperage won’t strike an arc—high amperage melts everything too fast.
Stick welding aluminum typically requires 180–250 amps for 1/8" electrodes on 1/8" to 1/4" thick material.
What determines amperage requirements?
Aluminum conducts heat much faster than steel, so more amps are needed to maintain arc stability and penetration. Other variables include:
- Electrode size (E4043 or E5356 aluminum rods)
- Material thickness
- Position of weld (flat, vertical, overhead)
Quick amperage rule:
Use 1 amp per 0.001" of material thickness, then add ~20% for aluminum’s high conductivity.
Table: Amperage for Common Aluminum Stick Welds
| Electrode Size | Material Thickness | Recommended Amperage |
|---|---|---|
| 1/8" (3.2mm) | 1/8"–1/4" (3–6mm) | 180–250A |
| 5/32" (4.0mm) | 1/4"–3/8" (6–9mm) | 220–300A |
| 3/32" (2.4mm) | Thin sheet (<3mm) | 90–140A |
At Prime, we rarely recommend stick welding for aluminum due to its narrow amperage window—we prefer MIG or TIG for consistent results.
What current do you need to weld aluminum?
Even a perfect electrode won’t help if the current’s wrong.
To weld aluminum, use high direct current (DCEP) or alternating current (AC), depending on the process and electrode.
Aluminum current options by process
- Stick Welding (SMAW): DCEP (reverse polarity), 180–300 amps
- MIG Welding: DCEP only, 100–250 amps depending on wire and thickness
- TIG Welding: AC current preferred for oxide cleaning, 80–200 amps
Aluminum requires more heat input due to:
- High thermal conductivity
- Rapid heat dissipation
- Oxide layer melting point of ~3,700°F
Table: Welding Aluminum Current by Process
| Welding Type | Current Type | Amperage Range | Notes |
|---|---|---|---|
| Stick (SMAW) | DCEP | 180–300A | For heavy-duty field work only |
| MIG (GMAW) | DCEP | 100–250A | Best for speed and thickness |
| TIG (GTAW) | AC | 80–200A | Best for precision |
Prime uses inverter-based machines that allow fine-tuning of aluminum-specific waveforms, especially for TIG welds on critical parts.
How many amps does aluminum welding use?
It depends—but always more than steel at the same thickness.
Aluminum welding requires more amps than steel—usually 25–50% higher—due to heat conduction and arc stability.
Average amperage ranges:
- Thin sheets (<1/8"): 90–130A
- Medium plates (1/8"–1/4"): 150–250A
- Heavy plate (>3/8"): 250–350A
Aluminum doesn’t show visual signs of heating like steel, so controlling amperage is key to avoid:
- Burn-through
- Incomplete fusion
- Cracking during cooling
Table: Aluminum vs. Steel Welding Amps
| Thickness (inches) | Steel Amps | Aluminum Amps |
|---|---|---|
| 1/16" | ~70A | ~100A |
| 1/8" | ~120A | ~180A |
| 1/4" | ~180A | ~250A |
| 3/8" | ~250A | ~320A |
At Prime, we configure each welding machine based on material and electrode using calibrated amp charts and operator testing.
What amperage to weld with a 7018 rod?
Steel welding rods like 7018 need much less amperage than aluminum.
For 7018 rods, recommended amperage is 90–130A for 1/8" rods on mild steel.
Amperage chart for 7018
This rod is designed for low-hydrogen structural steel welds. It has a soft arc and doesn’t need the high heat aluminum does.
Table: 7018 Welding Amps by Rod Size
| Rod Size | Amperage Range | Material Type |
|---|---|---|
| 3/32" (2.4mm) | 70–110A | Light steel sheet |
| 1/8" (3.2mm) | 110–150A | General steel use |
| 5/32" (4.0mm) | 150–210A | Heavy plate steel |
Trying to use this amperage on aluminum will fail—aluminum won’t melt or fuse properly at these settings.
At Prime, we use 7018 only for steel, and always select the correct amperage for clean, safe, high-strength joints.
Conclusion
Stick welding aluminum requires high amps, special rods, and experience—get it wrong, and your welds will fail.
Need aluminum parts joined right the first time?
Contact Prime today for certified welding, CNC-cut blanks, and full aluminum processing support.
We ship globally, quote fast, and deliver ISO-approved solutions with precision and speed.
Send an inquiry now and weld with confidence.
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