Surtak — Knife Sharpening Angles and Grits | surtak.com
Edge angles from 20 degrees per side down to 10, and the grit ranges that separate rough sharpening from fine sharpening.
A typical kitchen knife edge is ground at about 20 degrees per side, making an included angle of 40 degrees on a double-ground edge. That is the default geometry you restore when a stone is applied to a worn kitchen blade.
For very sharp knives the edge angle can be as little as 10 degrees per side, for a 20-degree included angle. The trade-off is less metal behind the apex: the edge starts cuts more readily but has less support.
Grit divides the work into two phases. Rough sharpening is done on water stones, oil stones, or medium grits of sandpaper; fine sharpening is done in finer grits. The rough phase removes enough metal to establish a clean bevel; the fine phase refines the scratch pattern left behind.
On narrow screens, swipe or scroll the plate sideways.
There is a practical ceiling. A blade polished to a finer edge, greater than 3000 grit or so, although technically sharper, can have a harder time initiating cuts on soft vegetables or fruits with a skin, such as tomatoes or bell peppers.
Damage also picks the grit. Nicks in an edge can be felt as obstacles when the blade is tested carefully on a soft surface, and a nick is ground out on the rough grit before any fine work begins.
Pick the angle first, then the starting grit, then the finishing grit — the sequence on the main page follows the same order.
Further reading