Cutting And Grinding Discs: Matching The Abrasive To The Job

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 TIG welding equipment is there for.

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.

Flap discs sit between cutting and grinding in terms of use, combining overlapping abrasive flaps to blend welds, remove coatings and finish surfaces with more control than a solid grinding disc. Every disc also carries a maximum operating speed printed on it by the manufacturer, and checking this against your angle grinder's rated speed is a basic habit worth building into every new batch you open.

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 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.

Most domestic UK properties are supplied with single-phase power, typically 230V, which is more than adequate for light-duty inverter welders used for hobby work, repairs and general fabrication. Three-phase supply, commonly 400V to 415V across three live conductors, is standard in industrial premises and delivers power more efficiently to heavier equipment, which is why higher-output welders and plasma cutters, including some Fronius and ESAB machines, are often offered in a three-phase version.