Supporting Aiba Corporation in Replicating
Ancient Japanese Tatara Steelmaking
Proterial, Ltd.
Proterial, Ltd. (hereinafter “Proterial”) will support Aiba Corporation (head office: Sanjo City, Niigata, hereinafter, “AIBA”) in replicating the ancient Japanese Tatara steelmaking method. AIBA is a processor and seller of Yasugi Specialty Steel. The company will replicate the ancient Tatara method at KOUBA no SAITEN (KOUBA FES 2026), an industrial tourism event that will be held in the Tsubame-Sanjo area and surrounding municipalities. From 9:30 a.m. to 5:30 p.m. on Saturday, October 3, 2026, AIBA will give a public demonstration of the ancient method. Specifically, this will involve the processes of inserting iron sand and charcoal into a clay furnace, destroying the furnace, and taking a kera (massive block of steel) out of it.
1. Background
Tatara refers to a traditional Japanese steelmaking method that uses iron sand and charcoal as its major materials. The Tatara steelmaking industry thrived in the San’in region, including Okuizumo, as the region was a center for producing high-quality iron sand and enjoyed rich forest resources. Since the Edo period, the local port of Yasugi (in Yasugi City, Shimane Prefecture) has prospered as a steel loading port for transportation by kitamaebune (northern-bound ships) to areas including the Tsubame-Sanjo area.
However, in the Meiji period, cheap steel began to be imported and domestically produced following the start of modern steelmaking. Driven by a sense of urgency, a group of entrepreneurs involved in Tatara steelmaking established Unpaku-Steel Limited partnership in 1899, which is the origin of the main plant of Proterial, the Yasugi Works. Unpaku-Steel shipped kera, tamahagane (high-grade steel) and rentetsu (cutlery steel) made using the Tatara steelmaking method to destinations across Japan. It also started to do business with a hardware wholesaler that was the predecessor of AIBA.
Up to date, Proterial, related parties in the Tsubame-Sanjo area, and AIBA have developed the mutual relationships they built on Tatara steelmaking for many years of their histories. Against this backdrop and in agreement with KOUBA no SAITEN’s objective of presenting the attractiveness of manufacturing, Proterial decided to support AIBA in replicating the ancient Tatara method (approved by the Society for Preservation of Japanese Art Swords) at the event.
2. Replication of the ancient Tatara steelmaking method
| (1) Date and time: | 9:30 a.m. to 5:30 p.m., Saturday, October 3, 2026 (Open to the public)*
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| (2) Place: | Vacant land next to AIBA’s head office (3203 Yada, Sanjo City, Niigata Prefecture) |
| (3) Details: | A mini-sized furnace similar to those made in the Nara period will be replicated for ancient Tatara steelmaking. Out of the entire process from building a clay furnace to the removal of the kera, a public demonstration will be given on the insertion of iron sand and charcoal into the furnace, the destruction of the furnace, and the removal of the kera. Note: For the hands-on experience that will be provided as part of the demonstration, please visit the website of AIBA. |
| (4) Support given by Proterial: | Dispatch of people who will engage in the steelmaking and the provision of materials |
Photos from a past replication of the ancient Tatara steelmaking method
- Media Inquiries: Corporate Communications Dept.
https://www.cntct.proterial.com/contact/publish/inquiry_eng?g=01&c=001-01 - Customer Inquiries:
https://www.proterial.com/e/contact/
(Reference)
KOUBA no SAITEN (KOUBA FES 2026)
Corporate profile of Aiba Corporation
| Founded: | 1861; current organization established in 1965 |
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| Head office: | 3203 Yada, Sanjyo City, Niigata Prefecture |
| Capital: | 40 million yen |
| Representative: | Ryoji Aiba |
| Business description: | Sale of custom-cut mold materials, sale of high-quality Yasugi Specialty Steel as high-grade cutlery steel, and sale of processed molding steel |
| URL: |
Yasugi Specialty Steel is a registered trademark of Proterial, Ltd.