The Naniwa Diamond DR-7504 sharpening stone has a grit size of 400. It consists of an aluminium plate with a diamond grinding layer on top.
Diamond sharpening stones are ideally suited for sharpening hard steels. You can even sharpen ceramic knives with these sharpening stones. These sharpening stones can be used with or without water. The advantage of adding water is that the sharpening residue is immediately washed away. Another incidental benefit of diamond is that it doesn't need to be sharpened in between uses. In principle, diamond sharpening stones always remain flat.
However, it's important to note that your diamond sharpening stones need to be pre-sharpened before the first use, because in the beginning they sharpen slightly coarser. After about five to ten sharpening sessions, they will reach their ideal functioning.
We offer the Naniwa Diamond series sharpening stones in six different grit sizes: 400, 600, 800, 3000 and 6000. Want to know which grit size you need? Then check out our video tutorial. You can use the following as a general rule of thumb:
- 120 to 600: suitable for pre-sharpening blunt knives
- 800 to 1000: suitable for sharpening and maintaining knives that are in good condition
- 2000 to 3000: capable of a result sharper than factory-ready
- 5000 to 10000: suitable for sharpening (polishing) knives until razor-sharp