Sharpening a kitchen knife
A typical kitchen knife edge is ground at about 20 degrees per side, giving a 40-degree included angle on a double-ground edge. Sharpening on a whetstone removes metal to form a new edge, and the work moves through three stages: grinding, steeling, and stropping.
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A typical kitchen edge sits at 20 degrees per side for a 40-degree included angle. Very sharp setups drop to 10 degrees per side for a 20-degree included angle.
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Rough sharpening happens on water stones, oil stones, or medium grits of sandpaper. Fine sharpening follows in finer grits until the scratch pattern is uniform.
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Grinding on a whetstone, steeling with a honing steel, and stropping on a razor strop or buffing wheel complete the edge. Honing as a word may cover either fine sharpening or straightening.
A blade polished beyond 3000 grit, although technically sharper, can have a harder time initiating cuts on soft vegetables or fruits with a skin.
Start at 20 degrees per side and choose a medium grit for rough work, then a finer grit for refinement.
A typical kitchen knife edge is ground at about 20 degrees per side, which makes a 40-degree included angle on a double-ground edge. If you want a very sharp knife, the edge angle can be as little as 10 degrees per side, for a 20-degree included angle.
Sharpening removes metal to form a new edge. Rough sharpening is done on water stones, oil stones, or medium grits of sandpaper; fine sharpening follows in finer grits. The grit you start with depends on how much metal you need to remove, and the grit you finish with decides how the edge behaves on food.
Schematics of the bevel geometry and the three stages.
| Setting | Angle per side | Included angle | What it is for |
|---|---|---|---|
| Typical kitchen edge | 20 degrees | 40 degrees | Everyday cutting on a double-ground edge |
| Very sharp setup | 10 degrees | 20 degrees | Maximum keenness, less metal behind the apex |
| Rough sharpening | — | — | Water stones, oil stones, medium grits of sandpaper |
| Fine sharpening | — | — | Finer grits after the rough pass |
| Polished beyond 3000 grit | — | — | Technically sharper, may drag on tomato or bell pepper skin |
| Edge testing | — | — | Nicks felt as obstacles on a soft surface |
| Steeling stage | — | — | Straightens the edge with a honing steel |
| Stropping stage | — | — | Polishes the apex on a razor strop or buffing wheel |
List of the documented facts this page draws on.