How to choose the right whetstone for your knives?

Learn how to find the right stone for your knives!

 

Using a sharpening stone can be considered an art, especially in Japan where making knives with sharp blades is part of their rich history. In fact, given that the process involves different steps (soak the stone, maintain a regular angle, etc), the usage of whetstones is often avoided by people without a lot of experience. It is not like using a manual sharpener or a sharpening steel, accessories with which honing a blade is much faster and easier. Nonetheless, once the technique of using a sharpening stone has been mastered, you will realise that it is with a sharpening stone with which you get the best sharpening results.

Choosing a whetstone, however, is not that easy. Due to the great variety of grains and materials available for the stones, it is important to stop and reflect on what is the best option for your kitchen knives. Selecting the right sharpening stone will enable you to maintain your blades in an effective way for a long time.

As you probably know, there are several different types of stones. Most of the whetstones found out there in the market are made of composite materials such as corundum powder (which is an ultra hard material). These stones are generally recommended for knives that have blades with a high HRC (hardness level).

There are also natural stones, which are made from materials that are directly taken from quarries. For example, the Arkansas stones are well known because they are composed of Novaculite, which is a cryptocrystalline rock found only in that region of the United States of America. They are used for maintaining kitchen knives as well as table knives, and their durability is quite impressive.

Since not long ago, it is also possible to find diamond sharpening stones, which have a surface covered with diamond powder. They are highly abrasive, and thus they enable you to reshape the edge of your blades in just a few minutes.

Choosing the right stone depends on the following criteria:

- the type of steel of your knife

- the degree of wear of the blade (how dull is it?)

- the frequency of the blade's use


Whetstones


Type of steel of your knife's blade

Depending on the brand and the knife range, the steel of the blade can vary a lot. For example, the standard types of steel have a hardness level of around 53 HRC in the Rockwell scale. The main characteristic of those types of steel is that they are quite "soft" as they usually have less than 0.4% of carbon content. In terms of sharpening, the softer the steel of a blade is, the easier it will be to sharpen it, but it will remain sharp for shorter time.

If we want to upgrade to a higher steel range, we can find types of steel going up to 58 HRC, which is in fact the type of steel that we find in the blades of Wusthof knives, which are widely appreciated by cooks all around the world. This could be considered to be the "ideal" type of steel for a kitchen knife's blade, because it provides the perfect balance between being easy to sharpen and remaining sharp for longer time.

At last, we have the most rigid types of steel, which are the ones that have high carbon content (1% or above). These types of steel are usually found in a large number of Japanese knives. The kitchen knives manufactured in the land of the rising sun (not all but most of them) often have blades made of very hard steel such as the VG10 steel. For these types of steel, the Rockwell hardness usually goes high as 61 HRC, and in some case, it can be as high as 63 HRC. It is important to mention that the harder a steel is, the sharper it is and the longer it lasts with a sharp edge. However, the more rigid the steel, the more fragile it is, because it is less flexible, and thus it is less resistant to strokes. That explains why most Japanese knives do not survive accidental falls in the kitchen. 

Here is a brief summary for a standard blade, and by a standard blade we mean a blade that is not blunt to the point of not being able to cut at all:

- Blades with low hardness (below 53 HRC): it is recommended to use whetstones with thick, coarse grains, because if you use a stone with fine grains for this type of blades, the sharp edge will not last very long. Therefore, you can use use sharpening stones of up to 800 grit. If the blade is fully blunt, you might also consider using a coarser stone as its abrasive surface will be ideal to reshape the damaged edge of the blade. In this case, you should not go above a 500 grit.

- Blades with medium hardness (between 53 and 58 HRC): can be honed with stones with grit ranging from 800 to 1000. These whetstones are ideal for doing the final honing of blades with lower HRC, as well as for doing the initial sharpening of blades with higher HRC.

- Blades with medium hardness (between 56 and 59 HRC): they can be honed with medium grains ranging from 1000 to 3000 grit. With these whetstones, you can truly give a remarkable sharpness to your blades, and in some cases, depending on the knife model, you can even obtain a razor sharp edge. If you would have to get only one sharpening stone, the best option would be to get a stone with 1000 grit, which is truly polyvalent as it adapts to most blades. 

- Blades with high hardness (between 60 and 62 HRC): must be honed with a fine grains whetstone, which will be perfect to polish the edge's surface. For these blades, we recommend stones with grit between 3000 and 8000. It is important to do the sharpening stepwise, because using a sharpening stone with fine grains is actually harder than using a coarse grains stone. This is why there are several combination stones out there with two faces that have two different grains so that you can do a stepwise sharpening: start with the less fine grains and finish with finest grains. The stones with such fine grains are well adapted for blades made of Blue Steel and White Steel.

- Blades with ultra high hardness (above 63 HRC): a stone of at least 8000 grit will be required. The grains of these whetstones are so fine that they are actually mainly used by sharpening experts, which are the ones who will know better how to truly take the best out of them.

 

How dull is your knife?

Of course, the advice given above depends on the degree of wear of your blade's edge. You must have in mind that if you are dealing with a fully blunt blade, a special type of care will be needed. That is why the double-sided whetstones are quite useful; they provide you 2 solutions in 1. You'll have one side with a coarser grain that you can use for sharpening a blunt blade, and you'll have side with finer grains, which you can use to finish and polish the edge of the blade. 

To make it clear, a blade with a high hardness level but that is significantly dull would have to be sharpened with a coarse sharpening stone (for example grit 240), because that low grit is abrasive enough to restore the blade's edge. Then, stepwise, you'll have to use stones with finer grains until you end up reaching the desired sharpness.

However, a blade with a low HRC level can be sharpened with a coarse grit stone (if the blade is dull), but there won't be any need to finish with a stone with ultra fine grains. This is because fine grains have almost no effect over "soft" steel, thus you'll end up spending more time honing the blade than the time during which the blade will keep its sharp edge.

 

How often you use your knives?

If you use your knife frequently, it is recommended to hone it regularly with a medium grains whetsone just as a way to maintain your blade's edge and avoiding to let it become dull. If you give an intensive daily use to your knife, it is important to hone it frequently so that you never completely lose its sharp edge. If you don't know how to do this, whether it is done with a sharpening stone or with a sharpening steel, we invite you to read our article in how to sharpen kitchen knives.

 

There are several other factors that need to be taken into consideration when choosing the right whetstone for your kitchen knives: the size of the stone, whether it comes with a base or not, how much water it absorbs... but all those factors can only be judged once you have and use the stone. However, to take a decision before buying a sharpening stone, all the advice given above should be a good guide for you.

To be ready for any eventuality, you can opt for double-sided whetstone, which gives you 2 different grains in 1, and thus you can get more complete results. To be more at ease whilst using your stone, you could consider getting a base for it (if not already included with the purchase of the stone) and a flattening stone, which could be used to flatten the surface of your whetstone as this one will surely wear off irregularly across its surface. For those who use their knives a lot, we advise you to buy a thick stone; it will be more expensive, but it will last more, and thus it ends up being cheaper in the long term. However, if you are just a hobby cook using knives at home, a fine stone should be fine.

If you still have a doubt or question about making the right choice, please do not hesitate to send us a message, and we'll be glad to help you out :)

 

Go have a look at all the sharpening stones available on our website:

Buy a sharpening stone on MyChefKnives.co.uk