Gritomatic Sharpening Stones are used for sharpening knives using Hapstone or Edge Pro sharpeners. The stones are made of silicon carbide and are designed for the hardest steels (up to 65 HRC). All stones are 6 mm thick and mounted on high-quality aluminum blanks with laser engraving.
It is advisable to use silicon carbide stones for sharpening knives made of hard stainless steel or carbon steel. Using silicon carbide stones to sharpen knives made of soft steel is not recommended, as it will cause the stones to wear an at the increased rate. However, coarse silicon carbide stones of 120 and 240 grit can be used as a universal stone due to their harder bonding.
Gritomatic synthetic stones made of silicon carbide and aluminum oxide can be labeled in either FEPA-F or JIS grit scale. To make grit uniform and customer-friendly, we have started the transition to the Japanese (JIS) grit scale for all Gritomatic waterstones. Old naming: F 120, F 220, F 400, F 600, F 1000. New naming: 120, 240, 600, 1000, 2500.
Gritomatic Silicon Carbide Stones are preliminarily lapped and does not require lapping after purchase.
Gritomatic Silicon Carbide Stones are recommended to be used with water as a lubricant. Soak the stone for 1-2 minutes and splash water on the stone's surface to prevent drying.
Both series are extremely good, but it's very difficult to answer the question. Parameters of an abrasive and bonding of Boride CS-HD series is the intellectual property of Boride. We can say for sure that Gritomatic uses harder bonding for 120 and 220 grit, and bonding of equal hardness for 400, 600 and 1000 grit. CS-HD offers 9 grits, while Gritomatic offers 5 grits only.