Understanding Duty Cycle Before You Buy An Inverter Welder

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.

Getting the right disc for the material and finish you're after saves both abrasives and time, and it's worth checking your current selection against the job list with a supplier who stocks a full abrasives range, such as plasma cutting equipment.

The practical difference comes down to what a machine can draw and sustain. A single-phase supply has a ceiling on how much continuous power it can deliver before tripping breakers or overloading domestic wiring, which is why the highest-output welding and cutting equipment is frequently three-phase only, or offers noticeably better duty cycle performance when run on three-phase. For workshops without an existing three-phase supply, bringing one in usually means an electrician and, in some cases, an application to the local distribution network operator.

Portability and durability matter depending on how the table gets used. A shop building large frames or vehicle chassis needs a solid, well-supported table that won't flex under load, while a mobile fabricator or someone working across multiple sites benefits more from a lighter, foldable design. Material and construction quality affect long-term flatness too, since a table that warps under heat from repeated welding stops being reliable exactly where it matters most.

The abrasive material itself matters as much as the shape. Discs formulated for steel typically contain aluminium oxide, while stainless steel usually calls for an inox-rated disc that's free from iron, sulphur and chlorine contaminants that could otherwise cause surface corrosion on the stainless. Aluminium and other soft, non-ferrous metals need their own dedicated abrasives too, since standard steel discs tend to clog quickly and produce a poor finish on softer materials.

For anyone starting out, talking through process, budget and set-up with people who deal with first-time buyers regularly is generally worth more than another hour of reading spec sheets, and that's exactly the sort of conversation the advice line at plasma cutting equipment is there for.