Stones are the best way to grind, sharpen and polish the cutting edge. This method is also used by Japanese knife factories. The Masahiro S-600 Rough sharpening stone is a flat, rectangular stone with dimensions 180x50x17mm and a gradation (number of grains, abrasive particles per cm 2 ) of 600, used for sharpening very blunt knives or knives with a damaged cutting edge. A stone of this gradation is one of the most frequently used tools for sharpening knives. The stone was placed on a plastic base equipped with rubber, non-slip feet. Before use, the stone should be placed in water for a few minutes and should not remain dry during sharpening. Masahiro recommends the following gradation selection for knives: 100 - 600 for very blunt knives and those with a damaged cutting edge 800 - 1000 for regularly sharpened, slightly blunt knives 1500 - 3000 for final smoothing and polishing Useful information: Do not wash in the dishwasher, wash by hand with a hand brush and mild dishwashing liquid. Can be used for any metal blades. Do not use for sharpening ceramic knives. Dry after use and store in a plastic container. Made in Japan     Gradation 600 (Rough) Length 180mm Width 50mm Height 17mm // Stones are the best way to grind, sharpen and polish a cutting edge. This method is also used by Japanese knife factories. The Masahiro S-600 Rough sharpening stone is a flat, rectangular stone with dimensions 180x50x17mm and a gradation (number of grains, abrasive particles per cm 2 ) of 600, used for sharpening very blunt knives or knives with a damaged cutting edge. A stone of this gradation is one of the most frequently used tools for sharpening knives. The stone was placed on a plastic base equipped with rubber, non-slip feet. Before use, the stone should be placed in water for a few minutes and should not remain dry during sharpening. Masahiro recommends the following gradation selection for knives: 100 - 600 for very blunt knives and those with a damaged cutting edge 800 - 1000 for regularly sharpened, slightly blunt knives 1500 - 3000 for final smoothing and polishing Useful information: Do not wash in the dishwasher, wash by hand with a hand brush and mild dishwashing liquid. Can be used for any metal blades. Do not use for sharpening ceramic knives. Dry after use and store in a plastic container. Made in Japan     Gradation 600 (Rough) Length 180mm Width 50mm Height 17mm // Stones are the best way to grind, sharpen and polish a cutting edge. This method is also used by Japanese knife factories. The Masahiro S-600 Rough sharpening stone is a flat, rectangular stone with dimensions 180x50x17mm and a gradation (number of grains, abrasive particles per cm 2 ) of 600, used for sharpening very blunt knives or knives with a damaged cutting edge. A stone of this gradation is one of the most frequently used tools for sharpening knives. The stone was placed on a plastic base equipped with rubber, non-slip feet. Before use, the stone should be placed in water for a few minutes and should not remain dry during sharpening. Masahiro recommends the following gradation selection for knives: 100 - 600 for very blunt knives and those with a damaged cutting edge 800 - 1000 for regularly sharpened, slightly blunt knives 1500 - 3000 for final smoothing and polishing Useful information: Do not wash in the dishwasher, wash by hand with a hand brush and mild dishwashing liquid. Can be used for any metal blades. Do not use for sharpening ceramic knives. Dry after use and store in a plastic container. Made in Japan     Gradation 600 (Rough) Length 180mm Width 50mm Height 17mm // Stones are the best way to grind, sharpen and polish a cutting edge. This method is also used by Japanese knife factories. The Masahiro S-600 Rough sharpening stone is a flat, rectangular stone with dimensions 180x50x17mm and a gradation (number of grains, abrasive particles per cm 2 ) of 600, used for sharpening very blunt knives or knives with a damaged cutting edge. A stone of this gradation is one of the most frequently used tools for sharpening knives. The stone was placed on a plastic base equipped with rubber, non-slip feet. Before use, the stone should be placed in water for a few minutes and should not remain dry during sharpening.