"The clay furnace, or tatara, has the appearance of a large altar. One can sense immediately that this is no ordinary method of steel production, bu.t a particularly Shinto experience that is performed in accordance with nature. The tatara clay furnace is approximately 2.7 meters long by 1 meter wide. The top edges curve downwards along its length, resembling the curvature of the torii-gate of a Shinto shrine. Prayers are performed in front of a nearby small Shinto shrine that houses the deity of metal production, Kanayago-no-kami, before production commences, and a portable shrine within the workshop overlooks the whole process. The workshop itself is separated from the material world by a sacred rope called a shimenawa."Here's the whole article.
Traditional Steel Production
In a short window of time in winter, traditional Japanese steel manufacturing takes place. It is a ritualized, Shinto process that results in the raw material that sword makers can use for Japanese swords and knives. The senior smith is designated as a living treasure, keeping the skills of ancient steel making alive.