Plasma Cutting Explained: What To Consider Before You Invest

Helmet choice comes down to the mix of processes you run and how much you're prepared to spend for extra sensors or a wider shade range, and it's a straightforward conversation to have with a stockist that carries several options, including TIG welding equipment.

An auto-darkening welding helmet uses a liquid crystal filter that switches automatically from a light state to a dark shade the instant it detects an arc, then reverts once the arc is gone. This replaces the older habit of flipping a fixed-shade visor down and up by hand, which meant either welding blind for a split second or lifting the helmet to check your position before striking the arc. 3M Speedglas is one of the ranges we point people towards most often for this, alongside other options across different budgets.

MIG (metal inert gas) welding feeds a continuous wire electrode through a gun, shielded by a gas supply, which makes it fast and relatively forgiving for general fabrication, sheet steel and repair work. Jasic's MIG range is one of the more popular starting points here, covering entry-level compact units through to higher-output machines as work scales up. TIG (tungsten inert gas) uses a non-consumable tungsten electrode with a separate filler rod, giving a slower but tidier result that's favoured for thinner materials, aluminium and stainless steel where finish quality matters. MMA, or stick welding, strikes an arc from a flux-coated electrode and needs no shielding gas at all, which makes it the most portable option and a common choice for outdoor or on-site work on thicker steel.

Abrasive discs look interchangeable on a shelf but perform very differently depending on what they're made from and what they're used on. Cutting discs are generally thin, designed to slice through material quickly with minimal heat build-up, while grinding discs are thicker and shaped to remove material from a surface or clean up a weld, rather than cut all the way through it.

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.

Ambient temperature and 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.