A knife is defined by two things: Its profile (blade shape), and its cutting edge (grind, or bevel). There are two types of cutting edges: The hollow grind and the flat grind.
Hollow-ground edges are concave. Flat-ground edges form straight angles.
Different grinds balance sharpness and edge retention with durability. Thinner grinds provide less durability: The cutting edge can dull or chip easier, but the edge is sharper. Wider grinds provide more durability and resistance to rolling and chipping, but they sacrifice some sharpness.
Terms to Know
- Concave: An inward curve.
- Convex: An outward curve.
- Flat / Cheek: The side of a blade.
- Spine: The top of a blade opposite the cutting edge.
Blade Grinds Reviewed
- The Hollow Grind
- The Flat Grind
- Angle and Thickness Matter as Much as Grind
The Hollow Grind
The Hollow Grind is concave and provides the sharpest cutting edge.
The hollow-ground bevel is formed by placing a blade blank (unfinished blade) against a grinding wheel. The wheel scoops a concave bevel out of both sides of the blade to form a thin, tall cutting edge. The edge of the blade is nearly vertical, providing razor-like sharpness.
The hollow grind is easy to spot. When light is shined on its cutting edge, the concave slope of the blade casts a shadow, creating a gradient that gets darker as the grind transitions from the blade’s edge to the spine.
Full Hollow Grind
The full hollow grind maintains its concave curve from the cutting edge to the spine, leaving no flats along the sides of the blade. This provides the thinnest, sharpest blade with the most cutting power. This cutting edge is also the weakest, and is typically reserved for delicate carving and thin slicing.
Full hollow grounds are most often found on filet knives, trailing point blades, straight razors, and kitchen knives like the Santoku.
Hollow Saber Grind
The hollow saber grind terminates the concave curve of the cutting edge along the cheek of the blade, leaving flats below the spine. This adds strength and stiffness to the blade, without sacrificing much cutting power.
Hollow saber grinds are often found on Bowie knives, Ka-Bars, Tantos, and bush knives, like the Buck Knives Frontiersman.
The Flat Grind
The flat grind is straight and balances sharpness with durability.
The standard flat-ground cutting edge is shaped like a “V” and provides a wider bevel than the hollow grind. This wider edge isn’t as sharp as a hollow-ground edge, but it’s more resistant to rolling and chipping. The flat grind comes in many variants, described below.
Full Flat Grind
The full flat grind’s “V” shape runs from the cutting edge to the spine, leaving no flats on either side of the blade. This bevel provides the thinnest blade compared to other flat grinds, making it an excellent choice for slicing, dicing, and fine cuts. Most kitchen knives are sharpened with a full flat grind. Beside a hollow-ground blade, a full-flat blade provides the most cutting power.
The full flat grind contains two bevels: The cutting edge bevel, and the primary or “cheek” bevel that runs up the rest of the blade to the spine. The cutting bevel’s angle is wider than the cheek bevel.
The full flat grind can usually be found on filet knives and typical pocket knives, like the Spyderco Paramilitary 3.
Flat Saber Grind
The flat saber grind provides the standard “V”-shaped cutting bevel, and a cheek bevel. Unlike the full-flat grind, the saber’s cheek bevel terminates along the side of the blade, leaving flats below the spine. Like the hollow saber grind, this sacrifices a bit of cutting power in exchange for added strength.
The “Scandi” grind contains just one bevel for the cutting edge, which runs partially up the cheek of the blade, leaving flats below the spine. This grind provides a very strong edge that can be ground to a thinner angle without sacrificing strength.
Sharpening a Scandi blade takes time. Compared to other flat grinds, the cutting bevel is long and requires more steel to be removed. This grind is often found on bushcraft knives, like the Tops Mini Scandi.
The convex grind forms a narrow “V”-shaped cutting edge bevel, and a cheek bevel that’s convex. The convex bevel terminates along the side of the blade, leaving flats below the spine. Think of the convex grind as an outward-curved saber grind.
The convex grind leaves more steel along the cheek, and the rounded sides of its blade provides high strength and resistance to chipping. The convex grind is most often found on axes, hatchets, machetes, Kukris, and survival knives like the Fallkniven F1X.
This uncommon grind sports a “half-V”-shaped cutting edge. One side of the blade is completely flat, while the half is ground for the cutting edge bevel. These blades may have one just bevel, like a “Scandi” grind, or two bevels, like a full flat or saber grind. These blades feature flat, sharpened tips.
The chisel grind is rarely found on anything but pry tools, survival multi-tools, and wood chisels, like the CRKT Razel GT.
Angle and Thickness Matter as Much as Grind
Other factors contribute significantly to how well a knife cuts, how long it holds an edge, and how much abuse it can take. Learn more about what matters with our other knife guides: