Understanding Duty Cycle Before You Buy An Inverter Welder

If you're not sure which supply a particular machine needs or whether your workshop can support it, it's a sensible question to put to a supplier before ordering, and the team at Tec Products can talk through the options against your existing set-up.

Switching speed, the time the filter takes to darken once it detects an arc, is worth checking against how you actually work rather than assuming faster is always better for every budget. For most general fabrication and repair work, a mid-range auto-darkening helmet with a sensible shade range covers the vast majority of jobs comfortably.

Duty cycle is one of the most misunderstood figures on a welder's spec sheet, yet it tells you more about real-world usability than the headline amperage does. It's expressed as a percentage over a ten-minute period at a given output, so a machine rated at 30% duty cycle at its maximum amperage can run for three minutes out of every ten at that setting before it needs to rest and cool.

A reliable, adequately sized compressed air supply is the part most first-time buyers underestimate. Undersized or contaminated air, whether from moisture, oil or an undersized compressor, is one of the most common causes of poor cut quality and shortened consumable life, so it's worth checking a machine's air requirements against what your compressor can actually deliver before you buy, not after.

Plasma cutting uses a jet of ionised gas, usually compressed air, forced through a nozzle at high speed and heated by an electric arc to a temperature hot enough to melt through electrically conductive metal. The molten material is then blown clear by the same jet, leaving a narrow, clean cut. Unlike oxy-fuel cutting, plasma works on any conductive metal, including stainless steel and aluminium, not just carbon steel. Hypertherm is the plasma cutting brand we get asked about most, and it's worth understanding the basics before comparing specific units.

Budget for a first machine is rarely just the welder itself. A gas cylinder and regulator for MIG or TIG, a decent auto-darkening helmet, gloves and basic workshop ventilation all add to the real cost of getting started, and skimping on the supporting equipment tends to cost more in frustration than it saves in cash. It's worth pricing the whole set-up before settling on a machine at the top of the budget.