News Release
July 24, 2024
Proterial, Ltd.

Kaoru Horio, Employee of Proterial Yasugi, Ltd., Appointed Murage of Nittoho
Tatara Steelmaking
On July 18, 2024, Kaoru Horio, an employee of Proterial Yasugi, Ltd. (Headquarters: Yasugi-shi,Shimane; CEO: Ichiro Kishigami; 100% owned by Proterial, Ltd.), was appointed murage (master) ofNittoho Tatara steelmaking by the Society for Preservation of Japanese Art Swords.
Proterial, Ltd., has been supporting Tatara steelmaking by the Society for Preservation of Japanese Art Swords, orNittoho, since 1977 (as Hitachi Metals, Ltd., at the time). Through this support, we are aiming to pass on the techniquesand culture of Tatara steelmaking, which is the basis of the current method adopted by the main plant of Proterial, Ltd.,Yasugi Works. On July 18, 2024, Kaoru Horio from Proterial Yasugi, Ltd. was appointed Nittoho Tatara murage.
Kaoru Horio joined YSS Service, Ltd. (now Proterial Yasugi, Ltd.) in 1989. In 1993, he started working at thecompany’s Torikami charcoal pig-iron making factory, also known as the site of Nittoho Tatara steelmaking, and there
he started his Nittoho Tatara practical training. Horio trained under the late Akira Kihara, a former murage, and has
been engaged in Tatara steelmaking ever since. Horio became an acting murage in 2014, and went on to devote himself
to acquiring knowledge and experience of Tatara steelmaking. Now, he has been appointed murage by Nittoho. Hewill also be recognized as a holder of a Selected Conservation Technique, tamahagane production (tatara-buki), by
the Agency for Cultural Affairs. Given the fact that Kaoru Horio has become a Nittoho Tatara murage, Proterial, Ltd.
wishes to support the succession of Tatara techniques and culture more than ever.
Comment from Kaoru Horio“I am honored to have been appointed murage of Nittoho Tatara, with their long history of steelmaking. Eventhough I feel I still have a long way to go in terms of technique, I will diligently work to fulfill my responsibilities
as a murage, trying to reach a level equivalent to my predecessors, including the late Mr. Kihara, my mentor andformer murage. In Tatara steelmaking, a murage is required to have a wide range of skills, such as the abilities toexamine raw materials and ensure material procurement. A murage’s steelmaking skills determine the quality ofTamahagane. As a Nittoho Tatara murage, I will work to develop my energy, stamina, and most importantly,
mental strength to fulfill my duties, and continue to pass on our traditional techniques in cooperation with themurage trainees.”

Photo: Kaoru Horio engaged in Nittoho Tatara steelmaking

Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, Japanwww.proterial.com/e1/2

What is Tatara?
Tatara is an ancient Japanese steelmaking method. It is used to produce tamahagane steel—a material essential toJapanese swords—out of iron sand and charcoal. In accordance with the Act on Protection of Cultural Properties, theAgency for Cultural Affairs has designated tamahagane production, also known as tatara-buki, as a SelectedConservation Technique (a skill identified as requiring conservation measures, among all those subject to conservation
as cultural properties).
Yasugi Works’ current method to produce Yasugi Specialty Steel was derived from this traditional Tatara method.
The techniques and spirit of Tatara steelmaking have been developed and succeeded into the production of Yasugi
Specialty Steel.
Nittoho Tatara has been promoted under the Society for Preservation of Japanese Art Swords.

■About PROTERIAL“Proterial” reflects the essence of our corporate philosophy, which consists of three elements: Mission: “Make the best quality
available to everyone;” Vision: “Leading sustainability by high performance;” and Values: “Unfaltering integrity” and “Unitedby respect.” It combines “pro-” with the word “material.”“Pro-” represents our “three pros”:
Professional — work that exceeds expectationsProgressive — a spirit that keeps challengingProactive —an enterprising attitude“Material” refers to the high-performance materials that our original technologies produce and underpinned by the three pros.
With our focus on solving customer issues and bringing new levels of value, we promise to contribute to the realization of asustainable society through the products and services that embody our philosophy.

■Proterial, Ltd. — Company Overview

Established: April 1956
Head office: Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, JapanCapital: 310 million yen (as of March 31, 2024)
Representative: Sean M. Stack
Representative Director, Chairman, President and Chief Executive Officer (CEO)Sales revenue: 1,033.2 billion yen (Term ended March 2024)
History: 1910: Founded as Tobata Foundry Co.
1937: Merged with Hitachi, Ltd.
1956: Established separately as Hitachi Metals Industries, Ltd.
2023: Company separated from the Hitachi Group, and renamed from Hitachi Metals, Ltd. to Proterial, Ltd.

Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, Japanwww.proterial.com/e2/2