Spyderco 306CBN Premium Bench Stone - Sharpening Stone for Knives, Tools & Blades - Ideal for Home, Workshop & Outdoor Use

This two grit (400 and 800 mesh) Cubic Boron Nitride bench stone is large enough at 3" x 8" to sharpen the largest knives with ease. The CBN grit cuts very fast on hardened steel, but can easily get clogged if you try to shape softer steel or nonferrous alloys. The CBN is bonded to both sides of a relatively thick ground steel plate, which ensures that the surfaces remain flat throughout the lifetime of the stone. The instructions indicate that the stone should be used dry, e.g., without honing oil oil, which is true and effective. I did find that it is helpful to wash the used stone surface(s) with WD-40 after a session of use, in order to float off the steel particles removed by the grit. The debris can then be easily wiped off the stone with a soft cloth, and the WD-40 evaporates relatively quickly thereafter. While I use the CBN bench stone occasionally for knife sharpening, my main use is for shaping steel parts for antique firearms. I have restored to shooting condition a number of firearms from the 1860s to 1880s, and often have to remove corrosion or fit replacement parts to the firearms. This is where the flatness of the bench stone comes in very handy. If you employ even reasonably uniform pressure when stoning parts, you can be assured that the resulting surfaces will be flat and true. Many "replacement" parts for antique firearms are made slightly oversize to accommodate the fact that dimensional standards were not entirely uniform. This bench stone makes reshaping and fitting slightly oversize parts relatively easy, though it can of course be tedious. I would say that this Spyderco CBN bench stone fills an important gap between coarser diamond stones and finer synthetic ceramic (e.g., Alumina) stones, and complements both for anyone interested in sharpening blades and/or finish shaping machine parts.