Japanese sharpening whetstone: which are the existents types and how to choose’em

Comment choisir des pierres à aiguiser

Every person in possession of a Japanese artisanal blade, whether beginner or professional, knows that to best maintain the edge of their knives, they must equip themselves with whetstones.

In this article we explain some basic concepts to know when choosing which stone to buy and / or use.

The different types of stones

In recent years we find more and more stones of different brands and different prices on the market.

Japanese sharpening stones can be divided into two main categories: synthetic stones and natural stones. We will not go into details for natural stones because it is a separate and much more complicated universe, but we will focus on synthetics for the moment. The biggest Japanese brands producing synthetic stones are: King, Naniwa, Shapton and Suehiro. These brands are safe references, but there are other suppliers who offer very good quality products. To do this, ask your trusted dealer for guidance. Each brand offers different ranges of stones, from stones for beginners to ranges of stones for professionals.

The different grain sizes and how to use them

Depending on the stage of your blade and the work you want to do, we will choose and use different stones with different grain sizes.

We can divide synthetic stones into 3 subcategories:

coarse stones with a grain between 200 and 600, these are stones used especially when one has to repair a knife, or make geometry corrections or even recreate the edge on an extremely blunt knife.

medium stones with a grain between 800 and 2000, these will be stones that we will see used to sharpen a knife maintained fairly regularly. So, depending on how often we sharpen a knife, we will choose which grit to start with. (e.g. once a month with 800 grit, once every 15 days with 1000 grit, once a week with 2000 grit)

fine stones with a grain between 3000 and 30000, which are called polishing stones. Sharpening a knife consists of removing material from the wire to recreate the edge, and by doing this we create burrs (micro-teeth) on the apex of the wire. We will therefore use the polishing stones to remove this morfil and obtain a very smooth and cutting edge.

However, you have to choose the grain of your stones carefully, because if you choose to sharpen a knife up to a grain of 10000, it will cut a lot, of course, but it will hold this edge for less time than if you had finished your sharpening session on a 5000 grain. This is why, depending on the steel that comes to make up your knife and the type of use we want to give it, we will choose what degree of sharpening to give it.

For example:
  • a sujihiki (slicing knife) with which you will only cut proteins such as meat and fish, you can opt for a polish that exceeds 6000 grit;
  • a gyuto (chef’s knife) that we will use with much more frequency and with which we will cut several types of food, we will therefore choose a polishing between 3000 and 6000

That said, for people who simply and humbly seek to maintain and sharpen their knives, two stones will be more than enough. One medium grain stone and one fine grain stone. It should be taken into account that the gap between the two stones should not be too large. For example suitable combinations could be:

  • 800 – 3000/4000;
  • 1000 – 4000/5000/6000 .