How to Choose a Welding Machine
The right welding machine depends on the process you use, the electrodes or wire you weld with, the power supply at your site, and how long you weld without a break. Here's what to check before you buy — or tell us the job and we'll suggest a machine.
1. Choose the process
- ARC / MMA (stick)
- Welds with coated electrodes (rods). Simple, portable and forgiving of rust and wind, so it suits fabrication, repairs and site work.
- TIG
- Gives clean, precise welds on thin steel and stainless steel. Needs argon gas, a regulator and a flow meter.
- MIG / CO2
- Feeds a wire continuously for fast, long welds in fabrication. Needs shielding gas (usually CO2 or a mix), unless you use gasless flux-cored wire.
- Plasma cutting
- Cuts steel, stainless steel and aluminium with compressed air. Needs an air compressor.
2. Match the current to your electrodes
Thicker electrodes need more current. Typical ranges for common electrodes:
| Electrode diameter | Typical current |
|---|---|
| 2.5 mm | about 60–95 A |
| 3.2 mm | about 90–140 A |
| 4.0 mm | about 120–190 A |
| 5.0 mm | about 170–260 A |
Choose a machine whose maximum current is at or above the top of that range. The electrode packet gives the exact figures for that rod.
3. Check your power supply
Single-phase 220 V machines run from an ordinary shop or house supply. Larger machines often need a three-phase 380 V line. Check the input voltage in the specifications before you buy.
4. Understand the duty cycle
Duty cycle is how much of a 10-minute period a machine can weld at a given current. 60% at 200 A means 6 minutes of welding, then 4 minutes of rest. For long, continuous jobs choose a higher duty cycle, or a bigger machine.
5. What else you'll need
An electrode holder and earth clamp, a welding helmet and gloves — and for TIG and MIG, a gas regulator and flow meter.
General guidance only. Always follow the manufacturer's instructions for your machine, gas and electrodes.