MIG welding
What thickness can you weld with mig welding?
Quick answer
A 180 A hobby MIG welds to about 6 mm properly in a single pass; 200 A+ machines handle 10 mm+ with prep and multi-pass. Under 1 mm needs care and 0.6 mm wire.
Numbers by machine/output class
| Thickness (mild steel) | Current | Wire | Gas flow |
|---|---|---|---|
| 0.8–1 mm | 40–60 A | 0.6 mm | 10–12 L/min |
| 1.5–2 mm | 70–110 A | 0.8 mm | 12 L/min |
| 3 mm | 110–150 A | 0.9 mm | 12–15 L/min |
| 6 mm | 180–240 A | 0.9–1.2 mm | 15 L/min |
| 10 mm+ | 250–320 A | 1.2 mm | 15–20 L/min |
Beyond single-pass
Thickness limits assume full-penetation single-pass welds. Bevelling the joint, multi-pass stacking and preheat on thick sections extend any process dramatically — that's how structural welders join 50 mm plate with the same physics. Match the machine class to the thickness you actually weld 90% of the time.