Ever since metal knives have existed, whetstones have been an integral part of knife sharpening.
Whether it’s historical bladed weapons, tools, or kitchen knives: Whenever metal was cut, the blade eventually had to be resharpened. Long before electric grinders or modern sharpening systems existed, the whetstone was the most important tool for this purpose.
And that principle has held true to this day.
A good whetstone allows you to sharpen the edge of a kitchen knife with precision. You determine the sharpening angle yourself, can control the amount of material removed by choosing the grit size, and—with a little practice—can achieve a very fine and clean edge.
But there isn’t just one type of whetstone.
Natural stones, synthetic grinding stones, water stones, and oil stones differ significantly in terms of material, hardness, grit size, bonding, and how they are used.
Which option is the right one, therefore, depends on which knife you want to sharpen and what result you want to achieve.
A versatile and proven sharpening tool for kitchen knives
Why the whetstone remains a classic to this day
A whetstone is a relatively simple tool. No complicated mechanics, no motor, and no preset grinding geometry.
The knife is guided by hand across the surface of the stone. As it moves, the abrasive grains remove material from the cutting edge.
It is precisely this simplicity that makes the whetstone so interesting.
If you master the correct angle and motion, you’ll have control over the entire sharpening process. You can restore a severely dull edge, repair minor damage, or further refine an already sharp edge using a finer stone.
Grinding stones are available as natural stones from specific deposits and as artificially manufactured stones. In synthetic stones, hard abrasive grains—such as corundum—are bonded together to form an abrasive wheel.
The differences between these stones are, in some cases, significant.
And that’s exactly why it’s worth taking a closer look.
Natural Grinding Stones
There are quite a few good natural whetstones available on the market. Some of them are well-known, almost famous: the Arkansas stone, the Belgian chunk, or the Japanese natural stones.
With natural grinding stones, the quality is not determined solely by the name of the rock. Among other factors, the mineral composition, the structure of the rock, its hardness, and the type and size of the abrasive particles are decisive.
That is precisely what makes natural grinding stones so appealing: Each stone is a natural product and may differ in its grinding performance from another stone of the same origin.
The Arkansas Stone
Among other things, the stones differ in their density and fineness. The denser Arkansas stones work very finely and are therefore particularly valued for finishing and refining a cutting edge.
A special type is the so-called Washita stone. It is more porous and works faster than the very fine, dense Arkansas stones.
The Belgian Flint
Belgian flint, often referred to as Coticule, is also one of the well-known natural whetstones.
Its abrasive properties are due to the natural abrasive minerals in the rock. As with other natural stones, there are different qualities and variations.
It is precisely these natural variations that make such stones appealing to many users. They don’t simply function like an industrially standardized abrasive; rather, they provide a unique sensation during sharpening and leave a distinctive finish on the cutting edge.
Japanese Natural Stones
Japan is particularly well known for its natural water stones.
There are a large number of different deposits and types of Japanese natural stone. They vary—sometimes significantly—in hardness, structure, and grinding characteristics.
Unlike industrially manufactured grinding stones, the performance of a natural stone cannot always be described by a single standardized grit size.
This makes selecting natural stones more challenging—but it’s also what makes them particularly interesting for experienced knife sharpeners.
Why Natural Grinding Stones Are Special
Natural grinding stones are not necessarily better than synthetic ones.
Synthetic abrasives offer the major advantage that the abrasive grain, grit size, and bond can be specifically manufactured and tailored to one another. This allows properties such as removal rate and grinding performance to be reproduced much more consistently.
Natural stone, on the other hand, has its own unique character.
For beginners, a good synthetic whetstone is therefore often easier to evaluate. However, those who delve deeper into the art of sharpening will discover a fascinating world, especially when it comes to natural stones.
Synthetic Grinding Stones
Synthetic grinding stones are widely used today. Unlike with natural stones, the abrasive grain, grit size, and binder can be specifically selected and manufactured. As a result, the stone’s properties can be reproduced much more consistently.
Abrasives used include, among others, aluminum oxide (corundum) and silicon carbide. The choice of abrasive depends, among other factors, on the desired removal rate and the material being machined.
Abrasive Grain and Binder
The abrasive grain is responsible for the actual material removal. The binder holds the individual grains together and plays a key role in determining how firmly they are held in the stone.
This is crucial for the grinding performance.
With a softer bond, worn-out or dull abrasive grains can break away from the surface more easily. This exposes new, sharp grains. Such a stone can work faster, but it also wears out more quickly.
With a harder bond, the abrasive grains remain in the stone longer. As a result, the stone wears down more slowly and retains its shape for longer. At the same time, such a stone may need to be dressed more frequently to ensure that fresh grinding surface is available.
The binder is therefore at least as important as the specified grit size.
Corundum – a classic abrasive
Depending on how they are manufactured and their design, abrasive grains vary in their properties. Therefore, the term “corundum” alone does not fully describe a stone’s abrasive behavior.
For the user, the most important factor is how well the abrasive grain and the bond are matched.
Why high-quality synthetic stones perform more consistently
With an industrially manufactured stone, the grain size, composition, and binder can be controlled. This makes it possible to achieve much more consistent grinding performance than with a natural stone.
That doesn’t mean that a synthetic stone is necessarily better.
But for anyone who wants to work regularly with a specific whetstone, consistent quality is a major advantage.
That’s why synthetic stones are often easier to evaluate, especially for beginners.
Water Stones – Grinding with Water
The term whetstone does not simply refer to a specific type of natural stone. Synthetically manufactured grinding stones can also be used as whetstones. The key factor is that water is used as the working medium.
Synthetic water stones are particularly common. They are often softer and more porous than traditional oil stones. During sharpening, worn abrasive grains break away from the surface and, together with water and debris, form a fine abrasive slurry. This allows water stones to work quickly and produce a very fine cutting edge.
Soak or just wet?
This is where the different water stones differ significantly.
Traditional, porous water stones often need to be soaked in water for a few minutes before use so that the stone becomes fully saturated with water. How long this takes depends on the specific stone.
Other modern water stones, on the other hand, are what are known as Splash-and-Go stones. With these, it is sufficient to moisten the surface with water before and during sharpening. Soaking for an extended period is not necessary.
That is why you should always follow the manufacturer’s instructions the first time you use it.
Wear and tear is part and parcel of the water stone
A soft water stone has one key advantage: it can work very quickly.
The downside is increased wear and tear.
Sharpening doesn’t just affect the knife blade; the whetstone itself changes as well. Over time, the removal of material can cause a slight indentation to form on the surface.
Next, the stone must be dressed. This process restores the surface to a flat condition. Especially with softer water stones, regular dressing is therefore part of routine maintenance.
This is not a defect in the stone, but rather part of how it works.
Why Water Stones Are So Popular
Water stones combine relatively fast material removal with excellent control over the cutting edge.
They are available in a wide range of grits and can be used for everything from repair sanding to a fine finish.
For everyday kitchen use, however, you don’t necessarily need a whole collection of whetstones. A well-chosen medium-grit whetstone can already do a great job for many knives.
If you want a particularly fine edge, you can continue working with a finer grit afterward.
Oil stones—an ancient tradition
Back when knives were still mostly made of carbon steel and were much more susceptible to corrosion, oilstones were widely used. Even today, they still have their place in knife sharpening.
Among the best-known natural oilstones are the Arkansas stones. There are also synthetic oilstones, such as those made of aluminum oxide or silicon carbide.
Why is oil used for sanding?
The oil serves as a working medium during grinding. It aids the grinding process and helps keep metal debris off the surface of the stone. As a result, the stone does not become clogged as quickly.
A dry oilstone, on the other hand, does not work as well because grinding debris can become lodged in its surface.
When it comes to kitchen knives, you shouldn’t use just any oil. Suitable sharpening or honing oils are specifically designed for use with whetstones. Vegetable oils or motor oils are not the right choice for this purpose.
Arkansas – the classic natural stone for oil
Arkansas stones are made of novaculite and are available in various degrees of hardness and styles.
The softer varieties work faster. In contrast, very dense and hard Arkansas stones work particularly finely and are often used to refine an edge that is already well-formed.
One of the special attractions of these stones is that they are very durable. They wear down much more slowly than many softer whetstones and therefore need to be dressed much less frequently.
Working with an oil stone feels different from sharpening with a modern water stone. The stone works more slowly and in a more controlled manner. For some users, that is precisely what makes it so appealing.
How to Properly Care for Oil Stones
Even an oilstone needs to be maintained.
Grinding can cause metal particles and worn-out abrasive grains to become embedded in the surface. Thorough cleaning helps restore the surface to working condition.
Depending on the stone, it may also be necessary to dress or refresh the surface. With hard Arkansas stones, however, this is required much less frequently than with softer water stones.
A good oilstone can last a very long time if cared for properly.
This makes it a classic and durable tool—especially for those who prioritize control and a good feel for the cutting edge over speed when sharpening.
How to Prepare a Whetstone Properly
The whetstone should be clean and as flat as possible. Softer water stones, in particular, wear down during sharpening and can develop a dip over time. When this happens, the surface must be dressed again.
For dressing, use a suitable, flat, and coarse dressing stone or a lapping plate. The surface of the grinding stone is worked on until it is once again uniformly flat.
With a water stone, for example, you can mark the surface with a pencil. As you dress the stone, the marks gradually disappear. This makes it easy to tell whether the entire surface has been worked on.
It is important to use a flat, level stone, because otherwise the grinding angle may change during sharpening.
Water or oil?
The type of working medium used depends on the grinding wheel.
Water stones are used with water. Depending on the stone, it is either soaked before grinding or simply moistened on the surface with water.
Oil stones are used with a suitable grinding or honing oil. Water and oil should not be interchanged arbitrarily. The stone is designed for the specific working medium.
The Right Stance
Place the prepared whetstone on a stable, non-slip surface.
A folded, damp kitchen towel can serve as a simple base for suitable stones. The most important thing is to make sure the stone doesn’t slip while you’re grinding.
During extended sanding sessions, you should also make sure there is enough water on the surface. Water carries away sanding debris and aids the sanding process.
Sharpening Kitchen Knives with a Whetstone
Now it all comes down to a steady hand and the right technique.
The biggest challenge in freehand sharpening is keeping the grinding angle as constant as possible. The angle doesn’t have to be precise to a fraction of a degree. What’s much more important is that it doesn’t change constantly as you move.
As a guide, you can start by visualizing the desired angle using a simple tool. For many kitchen knives, the sharpening angle is typically between 10 and 15 degrees on each side.
Die Klinge wird mit der Schneide auf den Stein gesetzt und in einer kontrollierten Bewegung über die Schleiffläche geführt.
Dabei sollte die gesamte Schneide bearbeitet werden – von der Spitze bis zum Kropf beziehungsweise zum hinteren Ende der Schneide.
Gleichmäßige Bewegung statt großer Kraft
Beim Schleifen kommt es nicht auf möglichst viel Druck an.
Entscheidend sind ein gleichmäßiger Winkel, eine kontrollierte Bewegung und ein passender Druck. Gerade bei weicheren Wassersteinen kann zu viel Druck den Stein unnötig schnell abtragen.
Führen Sie die Klinge immer wieder in einer ähnlichen Bewegung über den Stein. Versuchen Sie, den Winkel während der gesamten Bewegung möglichst konstant zu halten.
Mit zunehmender Übung entwickelt sich dafür ein Gefühl in der Hand.
Place the blade on the stone with the cutting edge facing down and guide it across the grinding surface in a controlled motion.
The entire cutting edge should be sharpened—from the tip to the bolster or the rear end of the cutting edge.
Smooth Movement Instead of Brute Force
When sanding, it’s not about applying as much pressure as possible.
The key factors are a consistent angle, controlled movement, and the right amount of pressure. Especially with softer water stones, applying too much pressure can wear down the stone unnecessarily quickly.
Move the blade back and forth across the stone in a consistent motion. Try to keep the angle as constant as possible throughout the entire motion.
With more practice, you’ll develop a feel for it in your hand.Beide Seiten gleichmäßig bearbeiten
When sharpening, one side of the blade is worked on first. Then the other side is sharpened.
It is not necessarily important to make exactly the same number of passes on each side. What matters is that both sides of the cutting edge are machined evenly and that the desired cutting edge geometry is achieved.
An important indicator is what is known as the burr. If a fine burr forms on the opposite side during sharpening, this indicates that the sharpening process has reached the cutting edge.
Next, the other side is processed.
In the third part of our series, we’ll discuss in more detail how this ridge forms, how to recognize it, and why it must be removed afterward.
Should I start with coarse or fine grit?
The grit size you need depends on the condition of the knife.
A very dull or damaged knife may initially require a coarser stone. A finer stone can then be used to further refine the cutting edge.
For a knife that has simply lost its working sharpness, however, a medium-grit whetstone is often sufficient.
That doesn’t necessarily mean you have to own multiple stones.
A well-chosen stone can go a long way in everyday kitchen use.
What grit size should a kitchen knife have?
The grit size of a grinding stone largely determines how quickly and how finely it works.
As a general rule: The coarser the grit, the greater the material removal. The finer the grit, the finer the cutting edge can be finished.
A coarse stone is particularly suitable when the cutting edge is very dull, is damaged, or needs to be reshaped.
For routine sharpening of a kitchen knife, a medium-grit stone is often sufficient.
A fine stone is used when the cutting edge needs to be further refined after the initial sharpening. This allows you to create a very fine and clean cutting edge.
Grob, mittel oder fein?
Man kann sich die verschiedenen Körnungen vereinfacht in drei Bereiche einteilen:
Grobe Körnung
Für starken Materialabtrag, Reparaturen und den Neuaufbau einer Schneide.
Mittlere Körnung
Für das eigentliche Nachschärfen stumpfer Küchenmesser und für den normalen Küchengebrauch.
Feine Körnung
Für das Verfeinern und Polieren der Schneidkante nach dem eigentlichen Schärfen.
Welche Körnung tatsächlich sinnvoll ist, hängt aber immer vom Zustand des Messers und vom verwendeten Schleifstein ab.
Ein häufiger Fehler besteht darin, möglichst viele und möglichst feine Steine kaufen zu wollen. Für ein normales Küchenmesser ist das nicht notwendig.
Ein guter Stein mittlerer Körnung kann bereits hervorragende Ergebnisse liefern.
Wer mehr aus seiner Schneide herausholen möchte, kann anschließend mit einem feineren Stein weiterarbeiten.
Coarse, medium, or fine?
For simplicity’s sake, the different grit sizes can be divided into three categories:
Coarse grit
For heavy material removal, repairs, and rebuilding a cutting edge.
Medium grit
For sharpening dull kitchen knives and for general kitchen use.
Fine grit
For refining and polishing the cutting edge after the actual sharpening.
However, the grit size that is actually appropriate always depends on the condition of the knife and the whetstone used.
A common mistake is wanting to buy as many stones as possible, and as fine-grained as possible. This isn’t necessary for a standard kitchen knife.
A good medium-grit stone can already produce excellent results.
If you want to get more out of your blade, you can continue sharpening with a finer stone.
Not all grit sizes are the same
When selecting a grinding wheel, it is also important to note that different manufacturers and abrasive systems do not always allow for a direct comparison of their grit sizes.
Therefore, the specified grit size alone does not tell the whole story about a stone’s actual grinding performance.
In practice, it makes more sense to view the stone as a complete system: abrasive grain, bond, hardness, surface, and working medium collectively determine how it behaves during sharpening.
Conclusion – the whetstone remains a classic
A whetstone is one of the simplest yet most versatile tools for sharpening knives.
Whether it’s natural stone, synthetic whetstone, water stone, or oil stone—each type has its own properties and grinding characteristics.
What matters isn’t owning the most expensive or finest stone. What matters is finding the right stone for your own knife and learning how to use it.
If you maintain a consistent grinding angle, work with controlled movements, and use the right grit, you can achieve an excellent edge using a whetstone.
And that is exactly what makes this whetstone a true classic to this day.
The third part of our series focuses on other ways to keep kitchen knives sharp: sharpening steels, sharpening belts, sharpening systems, roller sharpeners, and electric sharpeners.
FAQ
Frequently Asked Questions About Whetstones for Kitchen Knives
What grit should a whetstone for kitchen knives have?
For routine sharpening of a kitchen knife, a medium grit is often suitable. Coarse grits are primarily used for severely dull or damaged blades. Fine grits serve to further refine the cutting edge after the initial sharpening.
Which is better: a water stone or an oil stone?
Both systems work well, but they function differently. Water stones often allow for quick material removal and are available in many different grits. Oil stones generally work more slowly and in a more controlled manner and can last a very long time. Which option is better suited depends on the knife and on your personal preferences.
Does a whetstone need to be soaked before sharpening?
That depends on the specific whetstone. Some water stones need to be soaked for a few minutes before use. Others, such as so-called “splash-and-go” stones, simply need to be moistened with water. You should therefore follow the manufacturer’s instructions.
Does a whetstone need to be soaked before sharpening?
That depends on the specific whetstone. Some water stones need to be soaked for a few minutes before use. Others, such as so-called “splash-and-go” stones, simply need to be moistened with water. You should therefore follow the manufacturer’s instructions.
Can you sharpen a kitchen knife with a whetstone?
Yes. A whetstone works very well for sharpening kitchen knives. It’s important to use a suitable stone, the correct sharpening angle, and a controlled motion. With a little practice, you can achieve a very sharp edge.
Are natural whetstones better than synthetic ones?
Not necessarily. Synthetic whetstones offer the advantage of very consistent manufacturing and highly reproducible grinding performance. Natural stones, on the other hand, have unique properties and their own grinding characteristics. Which option is better depends on the specific application and personal preferences.
