Corrects blade distortion and increases the smoothness of the base material to enable subsequent machine grinding, polishing, etc. Depending on the steel material and process, distortion is adjusted in various ways.
In the pre-polishing stage, the distortion is adjusted by applying a rolling level adjuster. Correcting horizontal distortion improves the precision and efficiency of polishing.
In the case of the Leather knife, the distortion is corrected little by little by hitting both sides with a soft hammer. The inner face of the blade is adjusted to be slightly concave in order to facilitate re-sharpening by the user.