400 Grit Samura Whetstone. Samura Whetstones are the perfect choice for high-quality, precise sharpening on all types of blades, even the hardest ones with a hardness of 58 HRC or higher. With its 400 grit, this stone provides the ideal level of roughness for an even and effortless cut. The quality and homogeneity of the grains of this sharpening stone...