Cutting And Grinding Discs: Matching The Abrasive To The Job

Welding produces fume made up of fine particulates and gases, and the composition varies depending on the process, the filler material and any coatings on the base metal. Fume rises from the arc and, without adequate control, can build up in the breathing zone of anyone working nearby, which is why extraction is treated as a core part of workshop set-up rather than an optional extra.

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 welding helmets and PPE.

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.

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.

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.

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.