Naniwa diamond whetstones are incredibly hard, flat sharpening stones that use water as a cutting medium. Consisting of a 2mm-thick layer of diamond abrasive particles bonded to an flat, anodised aluminium plate, Naniwa diamond stones are incredibly hard, versatile and long-lasting.
Because these stones use diamond cutters to abrade your blade of choice, they can be used to sharpen harder materials than water stones are capable of. As well as high carbon steel, high speed steel and alloyed tool steels, they can cut glass, ceramic and even carbide. This means that sharpening ceramic knives, carbide cutters, chamfering glass plates and getting an edge on even the hardest modern blades is achievable with Naniwa stones.
The incredible hardness of their diamond abrasives also makes these stones fantastically hard-wearing. Whereas water stones require regular flattening, Naniwa stones maintain their flatness thanks to the extremely durable diamond compound and stable aluminium substrate. If heavy use does wear the plate slightly out of flat, we have redressed these stones with light passes of our adhesive backed sandpaper on a glass plate. Due to the hardness of these plates, however, we did use six strips (two sheets) of sandpaper to achieve the desired result. This process is rarely required, and we expect the 2mm layer of diamond abrasive to last a lifetime.
We offer the Naniwa stones in #600, #1000, #3000 and #6000 grits for a range of applications. The #600 and #1000 grits make excellent substitutes for water stones of similar grades, where the bulk of preparatory grinding and sharpening work takes place. The lower maintenance Naniwa stones speed up the sharpening process, especially when lots of blades are involved, or when particularly heavy work needs to be done to remove chips from a blade.
The #3000 and #6000 stones are excellent for edge finishing, as well as quick tune-up jobs. Professional chefs in busy kitchens appreciate being able to re-hone a knife with just a spray of water and without having to flatten or soak a stone. Woodworkers also enjoy the speed benefits of such a low maintenance stone, and can achieve a mirror finish in minimal time even on the hardest of blades.
Each Naniwa stone comes with a small nagura stone, which useful for re-dressing the surface after metal build up.
Prior to use, it is advisable to spray each stone with water or soak for a minute or two.