Blade grinds, explained

The grind is the cross-sectional shape of a blade from spine to edge — how the steel thins out as it approaches the cutting apex. It is distinct from the edge angle, which describes only the final tiny bevel at the very tip of that taper. Almost every knife listing quotes the edge angle and says nothing about the grind, which is backwards: the edge angle determines how sharp a knife starts, and the grind determines how it behaves once the food is past the apex.

This is why two knives ground to the same 15° per side can feel completely different. A thin, flat-ground Japanese blade parts a potato and lets the halves fall away. A thick, shallow-tapered Western blade with the same edge angle wedges, and the potato cracks ahead of the cut. Same apex, different geometry behind it.

Why "thin behind the edge" is the phrase to learn

If you take one thing from this page, take this: the property that most determines how a kitchen knife feels is how thick the blade is roughly 2–5mm above the edge. That is the zone the food has to push apart after the apex has separated it. A knife that is thin there glides; a knife that is thick there wedges, and wedging is what people are describing when they say a knife "does not go through" despite being sharp.

Japanese knives are generally thinner there than German ones, which is a much better explanation for why they feel superior on vegetables than any difference in edge angle. It also explains why a thin Japanese blade is worse on butternut squash: the same geometry that glides through soft material has less mass and less wedge to force a hard one apart.

Flat grind: the sensible default

A full flat grind tapers in a straight line from spine to edge. It is the most predictable geometry in food — thin enough near the edge to slice cleanly, with a consistent taper that neither sticks nor wedges dramatically. Most good gyutos and a lot of quality Western chef's knives use it, and if you are not sure what you want, it is the right answer.

Hollow grind: thin at the edge, and then a step

A hollow grind is cut with the face of a large wheel, leaving concave sides. Immediately behind the apex it is extremely thin, so it starts very sharp and is easy to resharpen. The catch is what happens deeper: as food passes the hollow it meets the full thickness of the blade fairly abruptly, which can cause wedging in tall, dense items. Hollow grinds are excellent on slicers and thin work, less ideal on a knife you use for everything.

Note that a hollow grind is not the same as a Granton or hollow edge. The oval dimples on a santoku or slicer are scallops ground into the flat of the blade to reduce suction; the grind itself may be flat. The two terms get used interchangeably and should not be — and neither has anything to do with serrations, which are cut into the edge itself.

Convex grind: strong, and it pushes food away

A convex grind bulges outward instead of tapering straight. It leaves more steel behind the edge, which makes it strong — this is why axes and heavy cleavers use it — and its curved face actively pushes material apart as it passes, which improves food release. On kitchen knives you find it on Chinese cleavers and on some premium Japanese blades where it is applied subtly. It is the hardest grind to maintain freehand, because there is no flat to rest against the stone.

Compound grinds and what German knives actually do

Most forged Western chef's knives are not full flat. They taper from the spine and then add a secondary bevel closer to the edge, giving a thick, strong spine and a workable cutting area. This is a deliberate durability decision — it is what lets a German knife survive impacts that would chip a thin Japanese blade — and it is also why those knives wedge more. The two facts are the same fact. See Japanese vs German chef knives.

Single-bevel grinds are a category apart

Traditional Japanese single-bevel knives are ground on one face only, with the other face flat or slightly hollowed. They achieve an extremely keen edge and cut with astonishing precision — and they steer toward the flat side, they are handed, and they sharpen completely differently. They are specialist tools, covered in single bevel vs double bevel knives.