Japanese sharpening stone King Deluxe F-3 with 4000 gritStones are the best way to grind, sharpen and polish the cutting edge. This method is also used by Japanese knife manufacturers.High-quality sharpening stone King Deluxe F-3 4000 is intended for final smoothing and polishing of the blade. The stone with dimensions 185x62x15  and gradation (number of grains, abrasive particles per cm2) 4000, is mounted on a plastic base equipped with rubber, non-slip feet. The pure material used to produce these stones is aluminum oxide Al2O3 (corundum).King  is a brand belonging to MATSUNAGA STONE CO., LTD., founded in 1948, which specializes in the production of various types of abrasive materials, including knife sharpening stones. The high quality of the offered products has made King stones recognizable and highly valued all over the world. Knife sharpening:Selection of gradation 220 - 600 when the knife is very blunt or has a damaged, chipped cutting edge 800 - 1200 for regularly sharpened, slightly blunt knives 1500 - 6000 for final smoothing, polishingSharpening1. Soak the stone in water for a few minutes before use. The stone should be wet all the time while sharpening. 2. Set the stone stably on the countertop. You can place a damp cloth or paper towel under the stone to prevent the stone from sliding. The knife should be positioned at a 15-20 degree angle to the stone. 3. Depending on the type of blade:- one-sided sharpened knife - sharpen 90% on one side and 10% on the other- double-sided sharpened knife - sharpen equally on both sides4. Once sharpening is complete, remove the burrs from the cutting edge. To do this, set the knife perpendicular to the stone and, maintaining this angle, gently move along the entire cutting edge, first on one side, then on the other side of the blade. MaintenanceThe stone should be washed and dried thoroughly after use. Over time, indentations may appear on the surface, which should be leveled, e.g. with a special leveling stone.