Cutting disc sizes explained
What 100 x 1 x 16 means, which disc to use for steel, stainless, tile and stone, and how to stay safe.
A disc label such as 100 x 1.0 x 16 gives three sizes in millimetres: diameter x thickness x bore.
Diameter
It must match your grinder: 100 mm (4″) discs for 100 mm grinders, 125 mm for 125 mm grinders, and so on. A bigger disc on a smaller grinder is dangerous, because the guard no longer covers it and the speed rating may be too low.
Thickness
- Thin cutting discs (about 0.8–1.2 mm) cut fast, with less heat and burr. Best for sheet, rods and pipes.
- Thicker cutting discs (2–3 mm) last longer and suit heavier sections.
- Grinding discs (about 6 mm) are for removing weld and metal. Never cut with a grinding disc or grind with a cutting disc.
Bore
Most grinders in India use a 16 mm or 22.23 mm bore; the flange must fit it exactly.
Which material?
Use discs marked for steel on mild steel, “inox” discs on stainless (they don’t contaminate it), and diamond blades for tile, granite and concrete.
Speed and storage
The maximum speed on the label must be at least the grinder’s rated speed. Keep discs dry and flat, check the expiry date on bonded discs, and throw away any disc that is cracked, chipped or has been dropped.