Читать книгу Classic Handplanes and Joinery - Scott Wynn - Страница 12

Structure, the second most important aspect of a woodworking blade, is the result of the change that happens in the original composition of the steel due to heating it and changing its shape with a hammer (or rollers), often called hot work. Heat causes the crystals of the steel to grow. Hammering steel when it is hot causes its crystalline structures to fracture and impedes growth as the grains fracture into smaller crystals. Before being hot-worked, the crystals of steel are randomly oriented and frequently inconsistent in size.

Through forging (repeatedly re-shaping with a hammer while the steel is hot), the grain aligns and knits together in the direction of the metal flow. Proper forging increases grain structure consistency. When exposed at the edge through sharpening, crystals consistent in size and orientation break off one at a time as the blade dulls, rather than breaking off randomly in big clumps. The consistency of the crystals allows for a sharper blade that stays sharp longer.