Sharpening Devices

For edge repairing

When an edge has larger chips or significant damage, a substantial amount of material must be removed to restore it. For edge repair, the best option is often to take the knife to a professional sharpener, who uses specialized equipment like rotating whetstones or belts to remove the necessary material quickly and effectively.

For home sharpeners, the process is more labor-intensive, but it can be done with the right tools:

Coarse whetstone with a grit of 400 or lower.
Belt sander or belt grinder (if available).
Tormek sharpening system (a professional-grade grinding system).

The goal during edge repair is to achieve a straight edge without chips. Once the edge is straightened, you can proceed with regular sharpening to refine the edge and restore sharpness.

For edge sharpening

For edge sharpening, the simplest option is to take your knife to a professional sharpener. However, a rounded edgecan be restored at home using various sharpening tools, all of which work by moving the blade against a harder medium at a defined angle, removing material from the cutting edge.

Pull through sharpeners

Pull-through sharpeners are the easiest and most convenient sharpening solutions, divided into two types:

Roll-sharpeners, where the edge is pulled over vertically arranged round rollers or discs in a 90 degree angle. There are roll sharpeners with metal or ceramic discs / rollers, and with one or more rollers for rough and fine sharpening. Neither do roll-sharpeners produce beautiful edges on a microscopic level, nor can they restore an edge to a top level sharpness. Still, for casual users who want a cheap and easy sharpener that just does the job of making the knife useable again, they are a good solution, definitely better than keeping the knife dull.

V-sharpeners, where the sharpening elements are arranged in a V-shape, and the knife is drawn through the V at a 90-degree angle. There are different sharpeners with varying sharpening results, from easy and inexpensive sharpeners that do an ok job, to semi-professional solutions like the ZWILLING V-Edge that can produce a good sharpness and with a clean, nice edge.

Sharpening steel/rod

The sharpening steel, often referred to as a honing rod, is likely the most commonly used sharpening tool and is frequently included in knife block sets. While its primary purpose is to straighten a bent edge (as explained in "Edge Maintenance"), it can also have a sharpening effect, depending on the coarseness and hardness of the rod.

For the sharpening process to be effective, the rod must be harder than the knife. Most traditional sharpening steels have a hardness range of HRC 61-64, which works well for softer knives. However, when it comes to hard knives with an HRC rating of 61 and above, these standard rods may not be suitable.

Sharpening steels are available in different materials and coarseness:

Sharpening steel with no or smooth ridges: the smoother the surface, the more it realigns the edge rather than removing material. This is the most common type, but it's typically not effective on harder knives (HRC >61).

Tungsten carbide rod: made from steel with a tungsten-carbide coating, it's harder than traditional honing steels and suitable for knives with higher HRC ratings. It's a bit more abrasive, removing a small amount of material while sharpening.

Ceramic rod: made of ceramics. Generally more abrasive than steel, so they remove material and sharpen the edge. However, they can break easily if mishandled.

Diamond rod: usually a steel rod coated with diamond particles, usually quite abrasive. It can remove a significant amount of metal, making it more suited for sharpening rather than just maintaining an edge.

Knives are sharpened or honed by holding the rod in one hand and guiding the blade down the rod at a consistent angle, matching the angle of the cutting edge, with the other hand.

While professional chefs are often seen honing their knives quickly on a rod, seemingly striking it with force, this technique is only suitable for knives with softer steel and wider edge angles. It’s not recommended for knives with harder steel and thinner edges, as striking the blade too hard against the rod can cause significant chipping. This is why using sharpening rods is generally discouraged for Japanese knives. However, if done gently, with controlled pressure while pushing the blade down the rod, the risk of damaging the edge is minimal.

Guided sharpening systems

The key to achieving a sharp edge is maintaining a consistent angle between the knife and the sharpening surface. This has led to the rise of guided sharpening systems, which allow for sharpening at various grits with an adjustable and stable angle. These systems are particularly popular among custom knife makers and knife enthusiasts, especially for outdoor knives. High-quality systems like the TSPROF or Edge Pro APEX are priced over $200, tend to be large, and require some practice, but they are capable of producing extremely precise and sharp edges.

Recently, the market has been flooded with cheaper clones (e.g., RUIXIN) at a fraction of the price. While they do function for sharpening, they tend to lack the sturdy build quality of the originals, making it harder to maintain a consistent angle and achieve a truly sharp, precise edge.

Electrical knife sharpeners

Electric knife sharpeners come in a wide range of prices and styles. They operate similarly to manual sharpeners but use electrically driven rollers or belts for faster material removal. While they can deliver acceptable to good sharpening results, there is a risk of damaging the knife if not used correctly.

Electric sharpeners are a convenient option for home users dealing with more heavily worn edges, but they don’t necessarily produce sharper or better results than many manual sharpeners, which are often easier and safer to use.

Whetstones

Although it requires some practice, many consider sharpening on whetstones to be the best method for achieving the sharpest results. Whetstones provide unparalleled control over the sharpening process, allowing for a precise, razor-sharp edge. For this reason, we’ve dedicated an entire section to the art of whetstone sharpening.