Review on 🔪 High-Quality Norton Grinding Wheel: Premium Bench & Pedestal Aluminum Oxide Wheel, Very Fine Grit - 6 Inch, Pack of 1 by Abdulkarim Sugge

Hardness is rated from A to Z, with "A" being the weakest bond and "Z" being the strongest. A weak bond is preferred for grinding harder materials, while a stronger bond is desirable for softer materials. A typical weak bond for steel is in the "F, G, or H” range. The average hardness is in the "I, J or K" range. The seller rated this as "K" hardness (see my question/answer above). In my absolute opinion, I would classify this as hardness A or B. By pressing the grain very lightly, an incredible amount of rock dust is created. You should also polish the stone after each use to ensure an even cut surface. It gives a nice smooth finish but wears out ridiculously quickly.