Abrasives
How to choose an abrasive disc
The right disc cuts clean and lasts; the wrong one wears out fast or, worse, lets go. Choosing comes down to the job, the material, and the safety numbers.
Get the disc right and it cuts clean, lasts and stays safe. Get it wrong and it wears out in minutes, tea-stains your stainless, or shatters. It comes down to the job, the material and the RPM.
We stock the Rocket range across cutting, grinding, flap and sanding discs in the sizes Australian grinders actually run. This walks through picking the right one, matching it to your metal, and the safety numbers to check before you fit it.
Match the disc to the job (cut, grind, blend or finish) and to the material (mild steel, stainless/INOX or masonry), then check the disc's max RPM meets or beats your grinder's before you fit it.
1.Which disc for the job
Rocket 115mm INOX Cutstainless, iron-freeShop these discsFour jobs, four discs. Pick by what you're actually doing to the metal.
| Disc | What it does | Thickness / use |
|---|---|---|
| Cutting | slices through metal or masonry at 90 degrees | thin (1.0-2.5mm); never grind on the face |
| Grinding | aggressive stock removal, weld dressing, bevels | thick (6mm+), worked at 15-30 degrees |
| Flap | grind, blend and finish in one - smoother, more forgiving | overlapping cloth flaps, by grit |
| Sanding (fibre/resin) | surface prep, paint removal, finishing | by grit, on a backing pad |
2.Match the material and size
Rocket 125mm Flap 40Gcoarse, fast blendShop flap discsTwo things beyond the job type decide the disc: the material and the fit to your grinder.
Material. Mild steel takes a standard aluminium-oxide disc. Stainless is the one to get right - use an INOX disc, made iron-, sulphur- and chloride-free, or the contamination will make the cut edge rust and tea-stain later. Masonry and concrete need a silicon-carbide disc or a diamond blade, not a metal disc.
Size and fit. The AU staples are 100mm (4"), 115mm (4.5") and 125mm (5"). Match the disc diameter to your grinder, and mind the centre bore - 100mm discs usually run a 16mm bore, while 115 and 125mm run 22.23mm. On flap and sanding, the grit does the rest: low numbers (36-40) are coarse and fast, high numbers (80-120) are fine for finishing.
3.Before you pull the trigger
Abrasive discs spin fast and fail hard, so three checks are non-negotiable before every job.
- RPM. The max RPM printed on the disc must equal or exceed your grinder's speed. A disc spun past its rating can burst.
- Guard on. Never pull the guard to fit a bigger disc - fit the right size instead.
- Right disc, right way. Never grind on the flat face of a thin cutting disc; the side load shatters it. And check the expiry - bonded resin discs have a shelf life (usually about three years), stamped on the centre ring.
If you want it confirmed for your grinder and material - the right disc, size, bore and grit - send us the tool and the job and we'll spec it. And if you're specifying to a standard, confirm the disc's certification against your requirement first.
Tell us the material, the grinder and the job, and we'll point you at the disc that cuts it - safely, and without the tea-stain.
Shop abrasives
Not sure which disc?
Tell us the material, the grinder and the job, and our team will spec the disc - size, bore, grit and all.
