Ozuku Asagi / Ozuku Asagi / 大突 YS (apex 150x25x5.5)

Natural Japanese sharpening stones rightfully occupy the top position in the hierarchy of sharpening bars. And this is really deserved, since the properties acquired by the blade when sharpening on Japanese natural stones are extremely difficult, and in most cases simply impossible, to obtain using any other known natural or synthetic sharpening bars. The uniqueness of the natural composition of these rocks lies both in a special type of minerals that work as an abrasive component, and in the properties of binders containing many unique impurities that affect the resulting quality of sharpening. In most finishing natural Japanese stones, particles of silicon dioxide work as an abrasive, averaging about 65% of the rock. Grains of silicon dioxide have a diameter of about 2-3 microns and the shape of rounded scales, which simultaneously provides both abrasive and head treatment of the blade surface. This allows very thin and at the same time aggressive removal of the processed material from the workpiece, leaving the surface cleanliness significantly higher than the correspondence to the particle size (on average, about 20,000 grit compared to synthetic counterparts). In addition, natural Japanese stones contain about 30% of various muscovite mica inclusions, in particular sericite, which is the main component of the released suspension and is a surfactant in the form of coolant. It contains a large amount of oxides of various metals (oxides of potassium, manganese, chromium, etc.), which give the stone a pleasant grayish-green hue and provide, in addition to abrasive and head processing of the metal, an adhesive polishing effect.
Japanese natural stones are classified according to the place of extraction (mine), color (which in most cases determines the stratum or layer of extraction) and hardness (the hardness of the stone is indicated by the letters Lv with the numbers 1-5, the hardest stones sometimes have the designations Lv5+).
This Japanese natural stone sharpening bar is made from rock from the eastern mines of Kyoto - Oozuku Asagi, and has a hardness of Lv4. Size 150x25x6mm, pasted on an aluminum blank with 45 degree bevels.
The stone works very comfortably and pleasantly. There is a slight velvety feel. Removal of material is initially quite intensive. After the stone brings the surface finish to a value corresponding to its grain size, metal removal practically stops, blackness practically does not stand out in the suspension, and the supply is smoothed out. The work resembles a solid Thuringian Escher of good quality. The Ozuku stone can be perfectly used with the use of nagura. It is an excellent stone for razors, quality knives and high quality carpentry tools.