Historically, there are three broad grades of Japanese sharpening stones: the ara-to, or "rough stone", the naka-to or "middle/medium stone" and the shiage-to or "finishing stone". There is a fourth type of stone, the nagura, which is not used directly. Rather, it is used to form a cutting slurry on the shiage-to, which is often too hard to create the necessary slurry. Converting these names to absolute grit size is difficult as the classes are broad and natural stones have no inherent "grit number". As an indication, ara-to is probably (using a non-Japanese system of grading grit size) 500–1000 grit. The naka-to is probably 3000–5000 grit and the shiage-to is likely 7000–10000 grit. Current synthetic grit values range from extremely coarse, such as 120 grit, through extremely fine, such as 30,000 grit (less than half a micrometer abrasive particle size).[citation needed]

These are very popular stones. 8" Dia-Sharps have a single grit per stone making them more expensive, but at 8" by 3" they are wider than the 8" DuoSharps, offering a good working surface. The 8" Dia-Sharp line also has the widest range of grits available from DMT, with extra extra coarse, medium extra fine and extra extra fine options not available in other sizes, so it is good line to consider. One coarse and one fine stone is a good starting point.


You've acquired a good chef's knife, you're using it almost daily to make tasty dinners for the family, and it's stored in a nice knife rack or a magnet for safekeeping. So why stop there? Keeping that knife's edge fine will make cooking not only safer but, let's face it, much more fun. Whether you've spent £150 on a high-end knife or under a tenner on a dinky paring knife, keeping it sharp is crucial. 
You will be given access to our useful online learning material: a set of videos and articles to help you improve your sharpening technique. These resources were made by professional knife sharpeners, specifically for beginners and intermediate sharpeners. The articles and videos will guide you and teach you knife sharpening from scratch, also covering more advanced techniques. You can also get in touch with us anytime if you have any questions concerning sharpening specific types knives.
The video above, from the How To You YouTube channel, explains everything you need to sharpen with a whetstone at home, and the best methods for doing so. Obviously, you’ll need a whetstone (as well as a few other things), and you’ll want to work near your sink or a bucket so you have easy access to water. Fill a container with water, then soak the whetstone in it until it stops bubbling. Inspect your blades for any trouble spots, and get to sharpening using the methods and motions described in the video; making sure to check your progress as you go. We’ve talked about sharpening knives with whetstones before, but this guide is a bit more thorough and the old video has since been removed.
When the block is intended for installation on a bench it is called a bench stone. Small, portable stones (commonly made of bonded abrasive) are called pocket stones. Being smaller, they are more portable than bench stones but present difficulty in maintaining a consistent angle and pressure when drawing the stone along larger blades. However, they still can form a good edge. Frequently, fine grained pocket stones are used for honing, especially "in the field". Despite being a homophone with wet in most dialects of modern English, whetstones do not need to be lubricated with oil or water, although it is very common to do so. Lubrication aids the cutting action and carries swarf away.
This is great combination but you don’t need them all to get started. As your budget allows, start with one stone and although I like to start with a coarse stone, the 400 Chosera is a little coarse to start the learning process with and you would need another stone in a higher grit to finish. So if you want to start with one water stone, and that is perfectly okay, select the 1,000 grit stone, it will deliver an edge that will startle you, with practice of course. Also, just having a water stone in your possession is going to motivate you, trust me.
Again, burr formation is critical to success and if you are using a 1,000 grit stone on a dull knife, you may be there for a while but it will form. If you are grinding on one side for more than 3-4 minutes, flip the knife and work the opposite side, always feeling for a burr with your thumb on the opposite side to which you are working on. Remember, the fatigued metal is being forced down the blade towards the edge of the edge by your actions and the abrasive properties of the stone.
Once sufficiently wet, it's time to position the stone on something solid, so it doesn't move about during sharpening. Many come with holders, but you can just place it on a slightly damp tea towel on the table. The stone should be roughly perpendicular to your body, though Warner told me it is sometimes easier to angle it ever so slightly to the right (if you're right handed). 

Table mounted device – Typically the manual powered table mounted sharpener looks virtually identical to the electric powered sharpener with a slot for each stage. Where they differ is that each slot in the manual powered sharpener has only one groove and you pull the blade through this groove toward you to sharpen the blade. Once the blade is sufficiently sharp you place it in the honing groove to refine the edge and pull it toward you again several times. If there is a third, cleaning, stage you repeat the process for that stage as well.
If your dull knives are no longer getting the job done or you're worried you'll cut yourself, you should sharpen your knives with a stone. Sharpening stones, also called whetstones, are made of natural or synthetic materials and they can be used dry, with oil, or with water. Once you've chosen a stone, simply run your dull blades over the stone until they're sharp again. If you've used an even hand, your knives will feel like new!
We’re happy to present something everyone has been waiting for – a combination diamond/ceramic whetstone that will handle all your sharpening needs. The newly-developed DC3 and DC4 whetstones consist of a fine diamond stone (25 micron) and a very special ceramic stone, made of synthetic sapphires. The advantage of these materials, although they get worn, will still keep their flat shape this is important when you sharpen your knife. And, since these materials are the hardest we know of, they will sharpen any steel, even these extremely hard powder steels. You don’t need any lubrication for these stone but now and then you should consider cleaning them with warm water and liquid soap. The stones might feel coarse from the start but will become smoother/better after some use. A leather pouch is included.
J. Kenji López-Alt is the Chief Culinary Advisor of Serious Eats, and author of the James Beard Award-nominated column The Food Lab, where he unravels the science of home cooking. A restaurant-trained chef and former Editor at Cook's Illustrated magazine, his first book, The Food Lab: Better Home Cooking Through Science is a New York Times Best-Seller, the recipient of a James Beard Award, and was named Cookbook of the Year in 2015 by the International Association of Culinary Professionals.
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