If your knife is very blunt, chipped or deformed, you need a sharpening stone of about 240# abrasive grains.
These coarse particles can eliminate the extra part on the blade and help you quickly repair a damaged kitchen knife.
If your knife is only rusty but not damaged, usually a medium sharpening stone of 1000~2000# is sufficient.
In addition, 3000# sharpening stone can be used for polishing the cutting edge. But if you want the knife to have a beautiful luster, 6000# and 10000# are indispensable, because this kind of fine particles can not only help the knife form a sharp edge, but also make the entire cutting edge as fine and smooth as a mirror. Moreover, the service life of the knife polished with 10000# grit will be longer than that of 3000# (or even 4000#).
