This stone series is especially suitable for sharpening tool blades as well as for honing the back, e.g. on chisels or plane blades. Thanks to its particularly hard bond, the stone remains flat for a longer time. These stones are ideal for extremely hard, low-alloy carbon steels (White and Blue Paper Steel). Before use, soak the stones in water for at least 10 minutes. It is not recommended to keep them in water permanently.