Belgian Blue Whetstone for KME - Gritomatic

Belgian Blue Whetstone for KME

For Hapstone and KME knife sharpeners (KME format)

Country of origin: Belgium Belgium

$18.30 USD 📊 Grit Chart


Belgian Blue Whetstones (BBW) are used for finish or pre-finish sharpening on KME or Hapstone knife sharpeners.

Belgian Blue Whetstone is mined in the Ardennes mountains in Belgium. BBW is natural slate with a high garnet content.

BBW stones are universal, and can be used to sharpen knives of any steel.


  • Working surface: 100 x 20 mm (4" x ¾"). Please note that the width is smaller than standard 1".
  • Weight: 40 g (1.4 oz)
  • Abrasive material: Slate

How to use

Belgian Blue Whetstones should be used with water. All that is required is to wet the BBW surface. There is no need to immerse the stone. During the sharpening, slurry with garnets are released from the BBW surface. The more garnets are released, the more abrasive the grinding compound becomes. Try to keep slurry on stone surface.

BBW stones do not have any minor defects. BBW stones always have a color pattern; this is not a defect.

BBW stone does not require any preparations. It is naturally lapped to extra-fine grit.

Q & A

  • What grit do these natural stones have?

    Grit terminology is not applicable to natural sharpening stones, including slates. The behavior of a natural stone depends on its density and how good it was lapped. However, experts estimate BBW as 3000 - 4000 JIS.

About Ardennes Coticule

Product reviews

Questions and answers

If you have a question regarding this product, please feel free to ask.

Grit chart

Courtesy of Mr. Wizard. Please read chart explanation in README.