When you need to remove 2-5 mm of concrete, start at a coarser grit than you think—usually 16/20 or 30/46—and step through 60, 120, 200, 400 before resin. Skipping a grit wastes time because the next finer disc cannot erase the previous scratch.
| Job | Metal-bond sequence | Resin sequence |
|---|---|---|
| Heavy stock removal (2-5 mm) | 16 → 30 → 60 → 120 → 200 | 50 → 100 → 200 → 400 → 800 → 1500 → 3000 |
| Light grinding (0.5-1 mm) | 30 → 60 → 120 → 200 | 50 → 100 → 200 → 400 |
| Maintenance / coating prep | 60 → 120 | Skip or 100 → 200 |
Our R3 round-segment shoes is stocked in 30/46 and 60 grit; ask for other grits.
Each grit cuts a specific depth of scratch. If you jump from 30 to 120, the 120 disc cannot erase the 30 scratch pattern—you will see it through every later step, even under polish.
Browse concrete grinding discs category for the full metal-bond range.
Only if you need to remove significant concrete. On a normal floor, 30 is aggressive enough.
When the previous scratch pattern is fully gone. Walk the floor in raking light.
For polished concrete, yes. For epoxy prep, metal bond 120 is the finish line.
Heavy grinding rewards a strict grit ladder. Start coarse, step every grit, and do not skip. contact JOY TECH for a full set sized to your project area.
