FAQ. Why the angle changes when I flip the blade on Hapstone R2? The angle difference is typical for all clamp-based sharpeners. But being typical does not mean you should ignore it. It's good to know what causes it and try to reasonably mitigate it. The angle difference for a clamped knife can be caused by: the sharpener improper clamping inconsistent factory grind undersharpening of one side Don’t make assumptions. Check it! Don’t “live with that”. You can make almost zero angle difference if you want. The sharpener check procedure It is very important to follow instructions accurately. Set all your...

The question looks simple but it's not simple at all. Abrasive cutting performance Abrasive cutting performance depends on many factors. Many relations can be explained, but not all. Sometimes, abrasive A has zero cutting performance on steel B, or causes blade chipping, or extreme stone dishing, or glazing, or balding... We often cannot explain the fact of specific incompatibility, we just accept it. Grit value is a major factor affecting cutting performance. The intuition tells "coarser" means "faster" (larger particles remove more metal). However, it does not work for extra-coarse grits. In the coarse grit range up to the optimal...