The Basics of Knife Grinds

We have reviewed a few knives both here on the website and on social media. However, knife reviews often overlook the fact that the reader may not be a “blade guy” or “blade girl.” We have some reviews of the awesome Spyderco Delica and Endura that we’ve been working on, but we decided to push them back a little, and give you some background knowledge on knives.  We may not turn you into a “blade guy” or “blade girl”, but you will have enough knowledge to understand the lingo when discussing knives. We believe that every survival kit should have at least one blade, and every person should have one, whether it’s for opening mail, or cutting a seatbelt in a car crash, etc.

You will often see the material of a given blade flaunted, with numbers and letters tossed around like alphabet soup. Examples of common blade steels can include: AUS8, 440, VG10 and then just add even more complexity there can even be pattern welded (also called Damascus) tossed into the mix.  However, for many of us the steel is not as important as the understanding what a given blade is capable of, and a good place to start building that understanding is with blade grinds.

Flat Grind

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Many Spyderco knives feature FFGs as part of their distinctive blade design.

A flat grind is produced when the blade is ground vertically on a contact wheel. There are several different variations of flat grind. These variations include: the full flat grind (from the spine all the way to the edge,) the sabre grind (approximately half way down the blade) and the Scandinavian grind (which is even lower on the blade.) What is important to note about a full flat grind (FFG) is that they will be thicker and heavier than a hollow ground blade. The reason is simple: Since the blade must be ground from the spine all the way to the edge the blade must be thicker to maintain its strength. Thus, when choosing a full flat grind blade, you need to be aware that it will be heavier than other options. The trade-off is that a FFG blades will almost always outperform hollow ground blades in daily cutting tasks, and are less prone to binding.

Hollow Grind

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With so much variety in blade shapes, designs and grinds it’s important to understand each component of a blade, and how it impacts performance. 

A hollow grind is created when the blade is ground horizontally on the contact wheel. The hollow grind produces a thin, and sharp edge. Many straight razors, skinning knives, and some martial arts tools (axes, short swords etc) feature a distinct hollow grind. Hollow ground blades draw the work towards the edge, this allows the hollow grind to excel in slicing tasks. A hollow ground blades common in a wide variety of styles, shapes and sizes, what is important to note is that a hollow ground blade will shine when cutting meat, string, and other soft items. However, since the grind does not reach all the way to the spine like in a FFG, there can be binding on harder materials (ever tried to cut a squash with a hollow ground knife?) This binding occurs because of the flat on the blade between the beginning of the edge and the spine. This flat causes friction and binding in harder substances.

Chisel Grind

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the Kershaw 3840, like many tactical blades features a Japanese inspired Tanto style tip.

If you own a tactical-blade chances are you own a chisel ground blade. While the bevel is technically a V-bevel it is only sharpened on one side. The benefit of the chisel grind comes from the tip strength and the overall edge retention. The blade geometry keeps the blade sharper longer. For this reason, chisel grinds are common among tactical blades and Japanese culinary blades. Chisel-ground knives can either be right or left handed and will pull in that specific direction, if you watch sushi chefs they will often compensate for the “pull” with their knife technique to create straight, even cuts.

Convex Grind

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the Morakniv Companion has a distinct convex grind.

The convex grind is a gently sloping grind which tapers to create the edge. A convex grind is the exact opposite of a hollow grind. An extremely durable blade geometry, this blade type shines in general use. Many peasant and Scandinavian blades such as products by Morakniv are convex grinds.

Compound Grind

A compound grind consists of two grinds. The primary grind which creates the blade geometry and then a secondary grind to produce a cutting edge. The benefit of this design is that you can generally achieve benefits from both grinds (for example a reduction in binding.) The con of this particular design is that it generally produces a very expensive blade.

 

 



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