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.
The figure changes with output. Turn the amperage down and the duty cycle climbs, because the internal components are working less hard. This is why a welder can feel completely different in a busy production environment compared with occasional home workshop use: someone welding continuously through a shift needs a much higher duty cycle at their working amperage than someone doing short repair jobs a few times a week. It's the kind of spec worth comparing properly across brands such as Kemppi and EWM, not just reading off the headline amperage figure.
The collet and collet body hold the tungsten in place and need to match its diameter exactly. A worn or incorrectly sized collet allows the tungsten to shift slightly during welding, which affects arc stability in ways that are easy to blame on technique when the actual cause is a consumable that needs replacing. CK Worldwide and Furick are two of the ranges we stock here, and these are inexpensive parts, but neglected ones cause a disproportionate amount of frustration at the torch.
Keeping a stock of the right tungsten types, collets and gas lens sizes for the work you do avoids a lot of avoidable downtime, and it's the sort of consumables range worth sourcing from a specialist supplier like welding equipment supplier.
Buying a first welder is easy to overthink. Rather than starting from a shortlist of machines, it helps to start from the work: what materials, what thickness, and how much of it will be done indoors versus outside or on-site. That single question narrows the choice between MIG, TIG and MMA far more usefully than comparing spec sheets in isolation, whether you end up looking at a Jasic entry-level MIG package or something further up the range.
Matching duty cycle to actual workload, rather than just chasing the highest amperage figure, is the difference between a machine that keeps up with the job and one that keeps tripping out halfway through it, and it's a question worth raising with a supplier before you buy, such as welding equipment supplier.