From the engineering aspect, in the periods when the theory of metallic crystal or phase transition was not resolved, sword craftsmen kept making an effort and achieved cutting tools that were excellent scientifically as well, which attracts much interest even now.
工学的側面からは、金属の結晶の理論や相変化の理論が解明されていない時代において、刀工たちが連綿と工夫を重ね科学的にも優れた刃物の到達点を示しえたことに今も興味の眼差しが注がれている。