Cup wheels vs grinding discs — what belongs on the truck
Crews mix these up and burn discs before lunch. Here is the practical split I use when stocking abrasives.
If your truck has one “grinding” bin and everything lives in it, you are paying tuition in disc metal.
Cup wheels and flat grinding discs are not the same tool with different marketing. They fail differently and they cut differently.
Cup wheels
Cups are for aggressive stock removal on concrete and masonry — edges, high spots, coating tear-off when the bond matches the job. Spiral turbo cups move material fast; they also leave a pattern you have to live with or finish later.
See the abrasives collection for cups we actually stock, including spiral turbo styles.
Flat grinding discs
Flats are the finish and blend tool. Wrong grit on a structural edge and you chase scratches instead of closing the job. Keep a short grit ladder on the truck, not one “universal” disc.
The stocking mistake
Buying whatever was on sale last month and calling it a program. Match bond and grit to the material you cut most in the next six weeks, then keep a thin emergency SKU for the odd job. If you are not sure, send me the material and the tool — I will not upsell you a shelf of orphans.
Get a quote with the tool RPM and the surface. That is enough.