The Grit Progression: Why Skipping a Stone Costs You Time

Under magnification a sharpened edge is not smooth. It is a row of tiny teeth, the ends of the grooves left by the last abrasive, and the coarser the abrasive the bigger the teeth. That is why a coarsely sharpened knife saws through a tomato skin and a polished one presses through it. Neither is wrong. A butcher's knife and a serrated bread knife both exploit the teeth deliberately; a paring chisel wants none of them because they tear the wood fibres it is meant to sever cleanly. Look at a freshly ground edge under a loupe and you can see the scratch pattern directly. Turn the blade so the light rakes across the bevel and the direction of the grooves shows plainly.

Work at each grit until the scratch pattern across the whole bevel is uniform and running in one direction, with no deeper grooves crossing it. Then move up. A useful trick: change the stroke direction at each grit — circles at the coarse stone, straight strokes at the medium, figure-eights at the fine. The leftover scratches from the previous stone then run visibly across the new ones and you can see at a glance when they are gone, instead of guessing. Time per grit falls sharply as you go up, because each stone is removing less and less metal. The coarse stone may take five minutes; the finish stone twenty strokes.

Stones dish in the middle because that is where the blade spends its time. A dished stone rounds every bevel put on it, and it does so gradually enough that the maker adapts and never notices. Flatten with coarse abrasive paper on float glass, or by rubbing two stones together. Do it often — a minute every few sharpenings, not an hour once a year. Pencil a grid across the stone face first; when every line is gone, it is flat. Use the whole face when honing, not just the centre, and the dishing slows right down. This one habit does more for edge quality than any upgrade in stones.