Grinding stone (slate) Guanxi 200*70*28

Whetstone Guanxi 5000 grit

The rock that Guanxi lapping stones are made of is a sapropel-humus type of oil shale and is predominantly distributed among these geological deposits. The composition of Guanxi shale includes 62.3% silicon oxide and 26.7% aluminum oxide. It is this fact, and also to a greater extent the form in which these compounds are present in this mineral, that determines its abrasive properties.

Guanxi shales also contain humic substances from 10%, which determines (in particular, humic acids) the dark color of the rock. There is also a fairly high content of iron oxides, which, released into the suspension during sharpening, have an additional polishing effect on the workpiece material.

The rock of Guanxi shale is quite soft, which ensures high grain renewal on the working surface of the stone and makes it possible to work effectively with relatively hard steels.

The grain size of the Guanxi shale rock is positioned as 3000-5000 grit according to the Japanese JIS system. Such a spread in the grit value is due not so much to the difference in the properties of the mineral itself, but to the different abrasive effect of the rock, depending on the coolant used (water, glycerin, oil, etc.). While the traditionally recommended fluid for shale work is usually water.

In care, the stone is quite unpretentious, easy to clean, relatively easy to level, if necessary, on glass, on silicon carbide powder.