Welding machine buying guide
ARC, MIG or TIG; current and duty cycle; single or three phase. What to check before you buy an inverter welding machine.
Inverter welding machines are light, efficient and easy to carry. Pick one by answering four questions.
1. Which process?
- ARC (stick): simple, low running cost, works outdoors and on rusty or painted steel. The usual choice for fabrication and repair.
- MIG: fast and clean on sheet metal and production work; needs wire and shielding gas.
- TIG: neat, precise welds on stainless steel and thin metal; slower and needs more skill.
2. How much current?
Current (amps) decides the electrode size and metal thickness. A 200 A ARC machine handles the common 2.5 mm and 3.15 mm electrodes used in gates, grills and frames. Heavier sections and 4 mm electrodes need more.
3. Duty cycle
The duty cycle (for example 60% at 200 A) tells how many minutes out of ten the machine can weld at that current before it must cool. For long continuous welding, choose a higher duty cycle.
4. Power supply
Check what is available where you will weld: single-phase 230 V or three-phase 415 V. Machines with a wide input voltage range cope better with low or fluctuating supply on sites.
Safety and accessories
Budget for a welding helmet (auto-darkening is easiest), leather gloves, and the right electrodes. Weld in a ventilated place and keep fire away from sparks.