Knife Sharpeners Buying Guide

Glossary

When sharpening knives, it is important to be familiar with the following terms:

• Bevel – also known as grind, is the shape of the blade edge.
• Edge – the sharpened, or bottom, part of the blade.
• Grit – how small or large the abrasive material on a sharpening stone is; the lower the grit number, the coarser the stone and vice versa.
• Honing – the act of maintaining the sharpness of an already-sharp blade.
• Sharpening – the act of physically removing metal from the knife to create a new edge.
• Spine – the top part of the blade
• Swarf – the fine, metal particles leftover after sharpening a blade.

Types of Knife Sharpeners

Electric Sharpeners

Many electric sharpeners utilize a 2 or 3 step process for creating, sharpening, and honing the edge on a blade. The first step utilizes a coarse grit to sharpen extremely dull blades and the last step uses a fine grit for honing sharp blades. When turned on, a sharpener will spin the sharpening stones, which, when a knife is drawn through the slots, sharpens blades to the desired sharpness. Most electric sharpeners have guides that allow the user to get the perfect angle, which makes them popular because they greatly simplify the precise task of sharpening knives.

Handheld Sharpeners

Similar to electric sharpeners, handheld knife sharpeners simplify the sharpening process, though they are generally limited by having fewer slots to sharpen with. One advantage handheld sharpeners do have is their portability. Their small size and manual operating method make them perfect for cooking professionals who frequently find themselves traveling. Depending on how the handheld sharpener is designed, you either draw the knife through the slots while the sharpener is placed on a flat surface, or the sharpener is drawn down the length of the blade while the knife is carefully held spine-down on a table or countertop. Both types of handheld sharpeners easily sharpen a dull knife back to perfect cutting form.

Sharpening Stones

The three most common materials sharpening stones are made of are Novaculite, aluminum oxide, and silicon carbide and they are commonly known as Arkansas, India, and Crystolon stones respectively. Arkansas stones are natural stones, while India and Crystolon are man-made. Arkansas stones vary from fine to coarse in grit type, where India stones are better suited for fine sharpening and Crystolon are better for initial coarse sharpening. Some stones have diamond abrasives mixed in to get the optimal cutting edge.

For more information how to use sharpening stones, view our handy sharpening stone article.

Sharpening / Honing Steels

Contrary to the name, most sharpening steels don't actually sharpen knives. The primary job of a sharpening steel is to hone a knife blade, though certain cuts, or styles, are able to do minor sharpening; however, steels that do sharpen knives should not be used in place of the above sharpeners. The four most common cuts are regular, diamond, combination, and ceramic. The differences between cuts are rather minimal, and choosing between them mainly depends on whether you want to have the option of sharpening and how much you are willing to spend. It is also recommended that you use sharpening steels with a matching knife brand because manufacturers specifically design their steels to hone their knives.

• Regular cut steels are the most common and well known, as they are made from steel.
• Diamond steels feature a coating of diamond abrasives similar to what can be found on some sharpening stones.
• Combination cut combines a smooth surface for honing and a rough surface for minor sharpening.
• Ceramic cut, as the name implies, is made of ceramic and can be used for minor sharpening to help align the blade.

Serrated Knife Sharpeners

Serrated knives can be difficult to sharpen with a stone due to the shape of the blade, and most common sharpeners, both manual and electric, will actually damage your serrated blades if used with them. However, there are certain knife sharpeners that are able to accommodate serrated blades, so you should always check the sharpener before purchasing. Manufacturers will state whether their sharpeners can be used with serrated blades in their manual or literature. We also provide this information in our product descriptions.

Common Bevel Types

As stated above, the bevel, or grind, is the shape of the blade edge. This can widely vary on what you intend to use the knife for, or in other words, how sharp and strong you want the blade to be. Also note that this is not an exhaustive list of bevel types and that some of these can be combined with others to make new bevels.

• Convex Bevel – This type of bevel features an outwardly curving taper, which keeps comparatively more metal behind the edge to make it stronger, while still allowing for a moderate degree of sharpness. This type of bevel requires a skilled hand to create on a sharpening stone, and it is commonly found on cleavers.
• Chisel Bevel – Only one side of the blade is ground down, while the other side remains flat. This type of bevel provides a very sharp edge and is commonly found on Asian culinary knives. Also, left- and right-handed varieties are available, depending on which side the bevel is on.
• Double Bevel – Also called a compound bevel, this type is most popular for Western kitchen knives. To keep the blade thinner and improve cutting ability, a second, back bevel is added above the edge bevel. Though not as sharp as other bevels, this type makes up in strength and resilience.
• Flat Bevel – Featuring a taper that begins at the spine of the blade, this bevel type is very sharp, yet hard to create because of the amount of metal that is removed. This limits its availability in commercial use.
• Hollow Bevel – This type of bevel tapers inward (opposite of convex bevel) to create an extremely sharp, but weak blade edge. This bevel is commonly used on straight razors.
• Sabre Bevel – Also called a V bevel, this type is similar to a flat bevel, but the taper begins around the middle of the blade, instead of the spine. Found on various kinds of kitchen knives, this type of bevel produces a lasting edge at the cost of cutting ability.

Blade Angles

Knife angle measurements represent the angle to which each side of the blade is sharpened. For example, a blade sharpened at a 20 degree angle actually has a total angle of 40 degrees. The most common angle for kitchen knives is 20 degrees; however, some manufactures make their knives with a 15 degree angle. In general, the greater the blade angle the stronger and more durable the blade will be, but you do lose sharpness the more you increase the angle.

• 30 – 35 degree angles are commonly found on cleavers or other blades used for chopping. Chopping requires a lot of force and angles as large as 30 - 35 degrees provide the blade with the strength and durability necessary to consistently perform this task.
• 25 – 30 degree angles are used on hunting, pocket, and other outdoor utility knives. These types of knives need to be capable of cutting and slicing in tough conditions not commonly experienced by kitchen knives, hence the large blade angle.
• 18 – 25 degree angles are the angles most often found on the majority of kitchen knives. These angles create a delicate balance between sharpness and durability needed for use in cutting vegetables, fruits, meats, and cheeses. Chef, boning, and carving knives all commonly utilize angles within this range.
• 12 – 18 degree angles are reserved for knives that need to be extremely sharp like fillet and paring knives. Because these angles create a weaker blade, they are used on knives that mainly do a lot of fine slicing. Any angle lower than this range is usually reserved for razors.

Note that even though certain angles and bevels tend to naturally match up in terms of sharpness and durability, that doesn't necessarily mean that they need to be used together. For example, Western kitchen knives usually utilize a double bevel and they usually have a 20 degree angle; however, it could be useful to put an angle as low as 15 degrees on double beveled chef knife. That said, it probably wouldn't make sense, or even be possible, to put a large angle on a hollow ground blade. The most important thing to keep in mind when determining the bevel type and blade angle is how you want to use the knife, so you can find the perfect balance of sharpness and durability.