Modern Tōkō and Power Tools — The Debate over Electric Furnaces and Grinders, and the Definition of Traditional Sword Forging

The forging of nihontō is highly regarded as a traditional craft that preserves ancient techniques. Yet the equipment actually used by modern tōshō is not exactly the same as that used before the Edo period. Some tōkō have introduced electric drills, electric grinders, and even electric furnaces. "Does using modern equipment negate tradition, or is it a rational evolution?" — this question has been a repeatedly debated topic in the sword world. This article examines the equipment situation of modern tōkō and organizes the different views on tradition and innovation.

"Modern" Equipment Found in Today's Smithy

When visiting a tōshō's workshop, one may find modern equipment alongside the traditional forge reminiscent of a hearth. Here are some representative examples.

• Electric grinder (grinding machine): Some tōkō use a motorized rotating grindstone for rough finishing of the blade after forging. The laborious rough-shaping stage that would take a very long time by hand sengake (scraping) alone is shortened using an electric grinder. In many cases, however, the work returns to handcraft at the finishing stage, with power tools used only for rough shaping.
• Electric drill and drill press: Some tōkō use power tools for drilling the mekugi hole. Because hand drilling requires time and physical effort, replacing it with a precisely positioning electric drill is judged efficient in some situations.
• Electric furnace (muffle furnace / atmosphere-controlled furnace): This is the most contentious item. The traditional forge uses charcoal (white charcoal) as fuel and regulates temperature by blowing air with bellows (fuigo). An electric furnace offers precise temperature control and high reproducibility, and controlling the atmosphere makes it easier to prevent decarburization and oxidation. It is known that some tōkō use electric furnaces for tameshiyaki (trial firing) and research related to hamon.
• Chain block and hydraulic press: Some tōkō use mechanical force to assist in forging that would otherwise require a large hammer. In the modern era, where the traditional uchiko (assistant striker) system has declined, the idea of supplementing with machinery to compensate for the physical demands of repeatedly swinging a heavy hammer has taken hold.

Approval and Registration of Sword-Making, and NBTHK Assessment

In Japan, making swords of artistic value requires approval to be obtained for each sword to be made (Article 18-2 of the Act for Controlling the Possession of Firearms or Swords and Other Such Weapons (Jūtōhō) (e-Gov Legislation Search)). A tōshō applying for approval for the first time must have devoted themselves for five or more consecutive years to honing their skills under a tōshō who has already received approval, and must have completed training conducted by the Commissioner of the Agency for Cultural Affairs, among other requirements (Article 2 of the Rules on the Authorization of Art Sword Manufacture (e-Gov Legislation Search)).

A sword made under such approval is registered as a shinsakutō (newly made sword) with the prefectural Board of Education, a registration certificate is issued, and the sword enters circulation as an art object. The assessment for registration is conducted on the basis of criteria such as whether the object is a nihontō whose shape, forging, hamon, carvings, and other features display beauty (Article 4, Paragraph 2 of the Rules on the Registration of Firearms and Swords (e-Gov Legislation Search)), but there is no explicit provision uniformly prohibiting the use of power tools. What matters is that the sword is "a nihontō made using tamahagane by traditional methods," and there is latitude in the interpretation of that phrase.

NBTHK (the Society for the Preservation of Japanese Art Swords), a public interest incorporated foundation, is the leading organization for sword appraisal and preservation activities, and also conducts assessment and commendation of shinsakutō. Its assessment criteria emphasize the quality of the finished sword — the beauty of the jigane, hamon, and shape — and the artistic value of the finished work is the axis of evaluation, rather than whether modern tools were used at some stage in the production process.

The Debate over What "Tradition" Means

Tōkō hold a range of views on this issue.

The "Results over Process" camp argues that the beauty, sharpness, and durability of the sword are what matter, and that there is no need to reject the use of better tools in pursuit of them. After all, the charcoal used in the "traditional forge" is not produced by exactly the same method as before the Edo period, and the form of the bellows has changed with the times. The point is that the answer changes depending on where one sets the standard for "tradition."

The "Process-Oriented" camp argues that the "efficiency" gained from using power tools simultaneously deprives practitioners of opportunities to acquire skilled technique. Within each hammer blow of handwork resides an embodied knowledge of the craft — a felt sense of the condition of the steel. If the rough shaping is handled by an electric grinder, the opportunity to read the steel's changes at that stage through hand and eye is lost. From the perspective of transmitting technique, this is seen as a long-term loss.

The "Materials as Core" camp positions tamahagane (steel derived from tatara smelting), charcoal, and water quenching as the three core elements of nihontō tradition, with all other tools regarded as relatively secondary. In other words, this camp holds that a sword forged correctly from tamahagane over charcoal and quenched in water is a "traditional nihontō," even if an electric grinder was used.

The Potential and Limitations of the Electric Furnace

The case of the electric furnace is especially divisive. An electric furnace capable of precise temperature control holds great value for research and educational purposes. Some researchers believe it is beneficial for young tōkō, when systematically learning the "relationship between temperature and hamon" in yaki-ire (quenching), to conduct controlled-variable experiments using an electric furnace.

However, some appraisers point out that a sword quenched in an electric furnace during the actual production process differs in the expression of its jigane and hamon from one produced by the traditional "charcoal forge and water quenching" method. An electric furnace heats with high uniformity, which is an advantage in some respects, but the complex hamon scenery created through a craftsman's dialogue with the non-uniformity of the forge is said to be difficult to reproduce.

Ultimately, the choice of tools for modern tōkō is largely a matter of each tōshō's philosophy and technical judgment. For audiences and collectors, coming to know how a given sword was made and understanding the philosophy of its maker before evaluating the work is the path to a deeper engagement with nihontō.