Degussit® Ruby Bench Stones are ideal for sharpening tools and gravers – even carbide. May be used dry or with Gesswein Stoning Oil. The pure, sintered crystals of synthetic ruby have an outstanding resistance to wear, which makes them more economical than other stones. They will not groove even after years of use. In addition to metals, they may be used on other materials such as glass, porcelain and quartz.  Ideal for sharpening knives and gravers made of high speed steel or carbide.  Often used to grind, touch up or debur steel and carbide parts.  Made in Germany from pure, sintered crystals of synthetic ruby. No bonding material is used, so these stones and files are extremely hard and resistant to changes in shape. This is particularly important for quality precision grinding and finishing. This 2-sided stone comes in a plastic storage box and is usable on both sides.