Using a sharpening stone is considered an art, especially in Japan where knives have pride of place. Due to the particular process (need to wet the stone, establish regular passages, etc. the use of a stone can scare people who are not used to it. However, once the step is taken, you will see that stone sharpening is of rare efficiency!
Choosing your sharpening stone is not easy! In view of the variety of materials and grains available, it is important to do a little inventory before getting started! By choosing the best sharpening stone for you, you will be able to maintain your favorite knives over time, with efficiency and ease!
Namely that there are different stones. The stones that we mainly come across are stones made of composite materials, for example corundum powder (which is an extremely hard material). These stones are generally recommended for knives with a high HRC (blade hardness index).
We also meet so-called natural stones, it is to say that they come directly from a natural material taken from quarries. For example, Arkansas stones are well known because they are composed of Novaculite, a quartz that is only found in this region. They are used on kitchen knives but also table knives for regular maintenance. They are foolproof durability.
Finally, for several years there have been diamond stones, the surface of which is covered with diamond powder. They are very abrasive and allow you to straighten the edge of your blades in no time.
Your choice will be affected by several main criteria:
– The type of steel of your knife
– The degree of wear of said knife
– Your actual use of the blade
It is important to take these 3 criteria into account, because they are really complementary and will help you make your choice.
The steel type of the knife
Not all steels are the same. Indeed, depending on the brands and ranges of kitchen knives, the composition may vary dramatically. Standard steels are for example included around 53 HRC. This steel has the particularity of being soft (because it contains little carbon, on average 0.4%). In short, the softer a steel, the easier it is to sharpen, but the less it will hold the sharpening over time.
If we want to go upmarket, we could approach steels pulling up to 58 HRC, which is the steel we find on Wusthof knives , which are very popular with professionals. This level of hardness is ideal since it is the perfect compromise between ease of sharpening and edge retention.
Then come the much more rigid steels, because they have been enriched with carbon. This is for example the case with many Japanese knives . These are made from special steels, for example VG10, which is very hard. You can easily go up to 61 HRC, see 63 HRC. It is still important to specify that the harder a steel, the sharper it is (or at least has the possibility of being, because its wire is more rigid and therefore will hold a razor-sharp finish) . However, the harder it is (ie very rigid), the more fragile it will be in use, because it is much less flexible. For example, you should not drop your Japanese knife. Also, hard steels hold sharpening much longer, because the blade will deform much less quickly despite your use.
A knife with a standard blade
We mean a knife whose blade is not dull to the point of no longer cutting hot butter, but which has just started to lose its sharpness
Low / medium HRC steels (we will say 53 to 56+, up to 0.6% carbon)
We can count on stones ranging from 800 to 1000. These grains can both serve as a finish for low HRCs , or as an entry point for high HRCs. It is not useful to go on finer grains because these knives will not be able to withstand the too subtle sharpening achieved by this type of stone for a long time.
Medium HRC steels + (from 56 to 59, around 0.7% carbon)
Can be sharpened with median / higher grains, with the 1000/3000 range. These stones give a real edge, see even razor on some models. If you had to choose only one stone, it would be the 1000 grit one which is very versatile. On the other hand and as said previously, if you have a lower HRC knife, no need to go higher than grain 1000.
Steels with high HRC (from 60 to 62, up to 1% carbon):
Should be sharpened with a fine-grained stone, which will polish their surface as well as possible. We can therefore count on a grain between 3000 and 8000. It is once again important to do it in stages because it is all the same more difficult to sharpen a knife with a fine grain. This is why there are a number of double-sided stones. The levels are progressive. In addition, these grains require a certain mastery to have a result that meets your expectations, the advantage being however that, due to its high grain, the stone will not degrade the edge if you do it wrong (not like with a low grain where you risk over-filing the steel). The edge is polished: these stones are, for example, very suitable for Blue Steel and White Steel.
Ultra high HRC steels (at 63 HRC, with more than 1% carbon)
A stone with at least 8000 must be used. These stones are also recommended for sharpening experts, who will really know how to exploit their capabilities.
Important point to note
Often, users perform the “sheet of paper” test to see if a knife has been sharpened. The latter is not very representative if you have a low HRC knife. Indeed, to cut a sheet without difficulty, it is necessary to achieve an ultra polished finish, and this is only possible from a grain of at least 3000. Suddenly, as we said, this kind of grain is not very useful for too soft knives, because the finish will not hold for long. Just because your freshly sharpened “soft” knife can’t cut a sheet of paper, then, doesn’t mean it wasn’t sharp, it just isn’t “designed” for such a degree of finish.
If you want to test the sharpness of your knife there’s some tests you can take to determine which type stone and level of sharpness you want. Check out Which sharpening stone to choose: 5 tests
The degree of wear of the knife
Obviously, the estimates presented above need to be qualified. We are talking here about an average carried out with equal wear and little pronounced. It must therefore be admitted that a very blunt knife will require more special care. This is why double grain stones are very practical. They have the advantage of offering you 2 solutions in 1. One side will offer a thicker grain to sharpen a duller knife more deeply, and the other side will allow you to refine the sharpening, and to remove the bit accumulated on the blade.
By way of comparison, a knife with a very high HRC, but being very blunt, should still be used with a coarse-grained stone (for example 240) , as it will be more abrasive and therefore more recommended for this type of work. Then it will gradually be necessary to wind it up to finer grains in stages, to finish the sharpening smoothly.
On the other hand, a weak HRC knife can be sharpened with a thick grit (for example 240 if it is very dull), but will not need to be finished with a too high grit for the finish (since the smoothness of the grain will have no effect on too soft steel and the time spent sharpening it will be much more important than the hold of the acquired edge).
The use of knives
If you use your knife regularly, it is advisable to sharpen it more often on a medium-grit stone, so as not to have to fall into the excessively abrasive grains which remove material from your knives. If you use a heavy-duty knife, feel free to give it a regular finish to keep it sharp. The impact will be less for your blade, whose wire will remain intact. Are you wondering how to sharpen a knife ? See our article on this subject in the advice section!
Some other factors will need to be taken into account, such as the binding agent for the material of the stone, the size of the stone (which must adapt to those of your knives), whether it has a base or not ( which facilitates the process), its degree of absorption, etc … but these characteristics can only be quantified with regular use. And yes, you have to get your hands dirty! 🙂
In short, to be prepared for any eventuality, you can opt for a double-grain stone, in order to ensure maximum efficiency for your knife. To be even more comfortable, you can also equip yourself with an additional plinth , or a leveling stone , made to flatten the surface of the main stone, which can become hollowed out with use. A little advice for those who use their knives very often: opt for a fairly thick stone, it will certainly be more expensive but you will gain over time, because you can use it for longer! However, if you use it at home as a private individual, a fine stone will do