Medium-coarse (Grit 800) whetstone hones knife edges Useful for dull and damaged blades Requires submersion in water before use 8-1/8 inches long, 2-3/4 inches wide, 1-1/4 inches thick Honing instructions and diagrams included Unlike Western man-made stones, water rather than oil is used on Japanese stones to prevent the surface from being clogged with metal particles. We offer two classes of stone: coarse and finishing. The coarse stones are 250, 800, 1000, and 1200 grit. The 250 and 800 grit are faster cutting and used for repairing nicked edges or reshaping a bevel. The 1000 or 1200 grit stones are used for the first stage of the actual sharpening. Japanese water stones are softer than Western styles causing a fresh, sharp surface to be continually exposed to the tool edge.