Plasma Cutting Explained: What To Consider Before You Invest

Ambient temperature and Tec Products Ltd airflow around the machine also affect real-world performance. A welder working in a hot, poorly ventilated space, or one that's been boxed in against a wall with no clearance for its cooling fan, will hit thermal cut-out sooner than the same machine used with proper clearance in a cooler environment. Keeping vents clear and giving the unit room to breathe protects both the duty cycle you paid for and the components inside.

Surface flatness and tolerance are the starting point, but fixturing is what turns a flat plate into a genuinely useful tool. Tables with a grid of holes or T-slots let you bolt down clamps, stops and jigs in repeatable positions, which speeds up repetitive fabrication and makes it far easier to hold parts square while tacking. A table without any fixturing options usually ends up needing extra clamps, magnets or improvised supports to achieve the same result.

Space and power supply are the other two practical constraints worth checking early. Confirming that a chosen machine will run comfortably from the electrical supply actually available in the workshop, and that there's room to work safely around it with materials laid out, avoids the common mistake of buying a machine that then can't be used the way it was intended.

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.

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.