Prepared Ninjas understand you can’t ever have too many knives, as they’re crucial to any EDC kit, car, and backpack. However, in order to preserve a knife’s versatility and safeguard it as long-lasting companion tool, it’s crucial to understand how to keep it properly sharp – and it all starts with the blade grinds (edge).
Common Blade Grinds Infographic
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Typical Blade Grinds
- Hollow grind — Characteristic of straight razors, yields a very sharp but weak edge which requires stropping for maintenance.
- Flat grind — The blade tapers all the way from the spine to the edge from both sides. Sacrifices edge durability in favor of more sharpness. A true, flat ground knife having only a single bevel is somewhat of a rarity.
- Chisel grind — Only one side is ground (often with an edge angle of about ~25°); with the other side flat. Many Japanese culinary knives tend to be chisel ground, which makes them sharper than a typical double beveled Western culinary knife.
- Double bevel or compound bevel — A back bevel, similar to a sabre or flat grind, is put on the blade behind the edge bevel (the bevel which is the foremost cutting surface) to keep the section of blade behind the edge thinner, improving cutting ability. Being less acute at the edge than a single bevel, sharpness is sacrificed for resilience: such a grind is much less prone to chipping or rolling than a single bevel blade. This profile is commonly found in Japanese swords, such as the familiar katana.
- Convex grind — Rather than tapering with straight lines to the edge, the taper is curved, though in the opposite manner to a hollow grind. Such a shape keeps a lot of metal behind the edge making for a stronger edge while still allowing a good degree of sharpness. This grind can be used on axes and is sometimes called an axe grind. As the angle of the taper is constantly changing this type of grind requires some degree of skill to reproduce on a flat stone.
Knife design is very much a science, given blade geometry and grind concerns, but a professional sharpener will know how to treat your blade. And if you’re looking for a reliable sharpener, take a look at Lansky.