Reproduction Processing Based on Ancient-Style Processing of Articles (Iron Sword with Golden Letters) Unearthed from the Sakitama Ancient Tombs

We investigate the iron sword with 115 golden letters unearthed from the Inariyama Tomb at the Sakitama Ancient Tombs site, and how the ancient engineer processed the iron sword at that time. For this purpose, wrought iron bars with the same components as the iron sword were manufactured and were used as samples in the experiments. We attempted to simulate ancient-style processing, using charcoal powders or ancient mud gathered from the Sakitama Tomb for the polishing slurry and natural stones (grindstones), wood, hemp fabric, or deerskins for the polisher. It was confirmed that wrought iron samples with a mirrorlike surface can be obtained by this ancient-style processing method. The quality of the surace is equivalent to that of a surface polished by the present diamond polishing method. Accordingly, it is assumed that the processing techniques used in ancient times were of high degree in skills