How to read a disc size
Abrasive cutting discs are described by three values. In 125×1×22.23, 125 mm is the disc diameter, 1 mm the thickness and 22.23 mm the bore. Most angle grinders in Europe use a 22.23 mm bore.
Disc types by material
| Material | Disc type | Note |
|---|---|---|
| Carbon steel, profiles, rebar | metal cutting disc | thicker discs (1.9–3 mm) are more robust |
| Stainless steel | Inox cutting disc | free of iron, sulphur and chlorine; does not cause corrosion |
| Concrete, stone, brick | diamond disc (segmented / turbo) | far longer life than abrasive stone discs |
| Ceramic, porcelain tiles | continuous-rim diamond disc | clean, chip-free cut |
Effect of thickness
Thin discs (1–1.2 mm) remove less material, so they cut faster, generate less heat and leave fewer burrs. Thicker discs withstand side loads better and are preferred for heavy cutting.
Rules for safe use
- The maximum speed on the disc (m/s or min⁻¹) must not be lower than the machine's speed.
- Always keep the guard fitted; wear eye, face and hand protection.
- Never grind with the side of a cutting disc.
- Do not use expired or damp discs.
Speed and peripheral speed
Discs are marked with the maximum peripheral speed (e.g. 80 m/s) and the corresponding speed (e.g. 12,250 min⁻¹ for 125 mm). A larger disc cannot be fitted to a small grinder because of the guard, and using a small disc on a large high-speed machine is dangerous. Check the machine and disc labels together.
| Disc diameter | Typical max. speed (80 m/s) | Suitable machine |
|---|---|---|
| 115 mm | 13,300 min⁻¹ | small angle grinder |
| 125 mm | 12,250 min⁻¹ | small angle grinder |
| 180 mm | 8,500 min⁻¹ | medium angle grinder |
| 230 mm | 6,650 min⁻¹ | large angle grinder |
Types of diamond disc
- Segmented: fast dry cutting in concrete and brick; rougher edge.
- Turbo: balance of speed and clean cut; for granite and hard stone.
- Continuous rim: chip-free cuts in ceramic and porcelain tiles; mostly wet cutting.
- Cup wheel (grinding): for levelling concrete and grinding screed.
Storage
Resin-bonded cutting discs are sensitive to moisture. Store them dry, flat and in the original packaging, and observe the expiry date printed on the pack.
