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Coarse sharpening stones

Coarse sharpening stones (grain size 46, 100, 220, 320) are used to restore the shape of a chef’s or pocket knife. As such coarse sharpening stones are also used for blunt knives that haven’t been sharpened in quite some time. These stones ensure that you don’t have to sharpen your knife for a long time with minimal results. The sharpening frequency depends on the use and, of course, quality of the knives. A blade with a harder type of steel will retain its sharpness longer than a blade made from a lesser type of steel.

Frequently occurring problems

Many people forget how important the use of the coarse sharpening stone is and sharpen their knives with a stone that is too fine while their knives are too blunt to be sharpened with a fine stone. The result: a couple of frequently occurring mistakes:

  1. The cutting edge is too thick to use properly
  2. The angle used to sharpen the knife is too big to cut properly
  3. The sharpening surfaces on both sides of the knife do not come together leaving you with a blunt knife.

The degree of bluntness determines which sharpening stone you should use first. Abovementioned problems can be resolved with the help of a coarse sharpening stone:

  • Start with a coarse sharpening stone to remove enough material and to make sure the knife becomes thinner
  • Use the right angle while sharpening the knife
  • Use a coarse sharpening stone to restore the shape of the fold and finish the process with a finer sharpening stone
  • Coarse sharpening stones remove more material and will, therefore, deliver faster results.

What is the right angle to sharpen a knife?

Each knife has its own thickness. An average chef’s knife is often about 4 cm high, a peeling knife about 1 cm. Determining the right sharpening angle can be tricky. The following picture shows you how to determine the right angle:

Which coarse stone do I need?

We have many different sharpening stones and combi-sharpening stones in our range. As such you can choose from many different coarse sharpening stones; not all coarse sharpening stones are the same. For damaged, and extremely blunt knives (when a sharp edge is no longer recognizable) the Naniwa water stones with grain 46 and grain 80 would be a great solution. These sharpening stones are mostly used to remove deeper irregularities in the blade. Because of the extreme coarseness of these stones we recommend you only use these stones when you are familiar with sharpening.

Popular options amongst the coarse sharpening stones are the Naniwa Chosera with grain 220 and grain 400 with which you easily sharpen blunt knives. In no time at all the use of these stones will already leave you with great results. A convex fold or uneven tip can easily be restored with these stones.

It is important to know that there are differences between the types of stones produced by Eden and Naniwa. This is the result of the materials used. The Eden sharpening stone with grain 800 is therefore not the same during use as the Naniwa stone with the same grain size. You can learn more about the differences here.

If you are not sure which stone you should use for your knives we are always willing to give you personal advice!


Do you have any questions? Don’t hesitate and call or email us. Or try to reach us via Facebook or Twitter. We will try to help you as best we can!

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