CS-HD will wear extremely fast when used on soft steel

The Straight Edge provides a level of accuracy far greater than that of a conventional metal ruler

When you switch between stones

sharpest edge without excessive trouble or frustration and for an extremely long time

boride pc stone for edge pro Grit:400 CS-HD will wear extremely fastBoride Sharpening Stones are used for sharpening knives on Hapstone Pro sharpeners. Boride offers a wide range of stones with different performance values and different rates of wear. Boride stones are made of aluminum oxide, with the exception of CS HD series stones, which are made of silicon carbide. All Boride stones are 6 mm thick and are mounted on high quality aluminum blanks. Stones that are 6 mm thick offer a longer life cycle than stock Edge