Different knives have different edges. And different edges require different sharpening treatments.
That's why there are commercial knife sharpening machines out there. These machines can sharpen one or several types of edges.
Choosing the wrong equipment to sharpen a knife will do more harm than good. Thus, getting the right sharpening machine is vital if you want to keep the edge of your knives in tip-top shape. But if you think all knives look the same, how will you take care of your blunted knives?
We've prepared a cheat sheet for you containing the different types of edges and sharpening equipment. Plus, we throw in some knife sharpening tool recommendations to look for when you finally decide to get those blades out of their safe storage and grind them back to peak condition.
Before you consider taking on sharpening your blades, you have to get the fundamentals down first. Edges have different grind profiles, which will require different sharpening equipment for you to sharpen them correctly. Here are some of the basic grind profiles.
The hollow grind is a concave edge, meaning it curves inward. Often, a grinding wheel shapes blades with a hollow grind, resulting in a thick spine that can resist shock and a very thin edge with an astounding sharpness (think razor blade).
The same thin edge of the hollow grind is also its undoing as it can be prone to chipping if used vigorously. You will see this type of grind commonly used on small knives and razors, and you must sharpen them with an electric-powered knife sharpener machine to get the precise angle and avoid damaging the blade's edge.
If a hollow grind curves inward, the convex grind curves slightly outward. This type of blade grind reinforces the blade for use against chopping hard items. The convex grind gives a sharp edge with little compromise to the blade's thickness, and the result is a strong edge that can resist chipping and denting.
The convex grind is an artisan's grind choice because shaping the blade this way requires skills to pull off. Collectors' knives usually have this type of grind.
If you're going to sharpen a knife or tool with a convex profile, it's better to use mechanical sharpening tools as electric-powered ones might ruin the convex of your blade if you grind it with an incorrect angle or duration.
This type of grind profile is flat on one side and has a sharp angle on the opposite. It's a sharp edge in the sense that the total edge angle is cut in half because only one side is beveled.
The chisel grind is convenient to sharpen because you don't have to worry about balancing the sharpness on both sides of the blade for it to be sharp. On the other hand, its lowlight is that it doesn't quite cut symmetrically. Having only one beveled side, the cut tends to lean on the side with a slope. These types of blades are often best for skinning and filleting soft items.
You can sharpen this grind type with either a mechanical sharpener or an electric-powered knife sharpening grinding machine. It will still yield a superior edge without much risk to the blade.
The flat grind profile is the most versatile of all. The blade with this profile has a “V” shape, making the spine thick and the edge not too thin such that you can even add a second bevel to it. The edge angle supports a wide variety of knife activities like chopping, slicing, and mincing.
You will commonly find the flat grind on functional knives like kitchen knives, hunting knives, and other commercial knives because it's easy to produce.
This grind profile may not be as sharp as the hollow grind or chisel grind, but it's good enough for the job and can withstand a good amount of beating outdoors or in the kitchen.
You can sharpen the flat grind with both mechanical knives and tool sharpeners or an electric-powered one.
Electric knife sharpeners are automatic. You just plug them on an outlet, switch them on, and place your knife on the machine. You only need to pull the knife, and the machine does the work. It's like having a portable grinder.
Using an electric knife sharpener has a lot of advantages. For one, it yields better edge retention. The sharpener puts the knife on the coarse grinder for a prolonged time, making the edge more refined. Another advantage is its flexibility. You can use a knife sharpener tool for just about any knife.
However, it also has a disadvantage. It isn't easy to control some aspects like angle grind and intensity. If you're not careful, you might end up damaging your knife permanently.
Recommendation: Goweil Baler Knife Sharpening Machine
The Goweil Baler is a type of electric-powered knife sharpener. While you can use it for hollow-grind knives with just an adapter, this heavy-duty knife sharpening machine is best used for large chisel blades and agricultural cutting machines. The adjustable grinding and angle radius features of this sharpening machine are also perfect for bladesmiths that need to do major sharpening tasks.
Using these types of sharpeners requires more effort on your part. Mechanical sharpeners look like their electronic counterparts but without the machine. You insert the knife and pull it back manually. For quick honing, handheld mechanical sharpeners are also an option.
What mechanical sharpeners lack in power, they make up for with speed. Some mechanical sharpeners can bring knives to near factory-edge quality with just a few strokes, so it doesn't require as much time to get them ready. On the other hand, they trade off edge retention, meaning you might have to sharpen your knife again the next time you use it.
Recommendation: AccuSharp Knife and Tool Sharpener
This unassuming sharpening tool from AccuSharp is a mechanical type of blade sharpener that performs well on most popular grind profiles, such as the flat, convex, and hollow grinds. It is a handy kitchen companion for cooks who want quick honing of their cutting tools prior to food preparation.
The AccuSharp knife and tool sharpener uses tungsten carbide as a sharpening material, which can restore the cutting edge of your knife with just a few strokes not lasting more than ten seconds. It’s handheld and portable enough for you to store in your kitchen drawer, too.
Sharpening may look like a straightforward task, but it involves a lot of technical details underneath. Knowing your grind profile and what type of sharpening equipment you should use can spell the difference between a well-functioning knife and one destined for disposal. Know your grinds, select the appropriate sharpener, and make your knives last a lifetime.