Mass Sword Production in the Sengoku Period: Kazuuchi, Custom Orders, and Ashigaru Armament
* Image is for illustrative purposes only.Table of Contents
The Explosion of Sword Demand in the Sengoku Period
The Sengoku period, triggered by the Onin War (1467), drove demand for Japanese swords to historically unprecedented levels. From shugo daimyo down to foot soldiers, every level of the warrior class required swords and companion blades—far exceeding the scale of bespoke production that had served the court aristocracy.
What Are Kazuuchi (Mass-Produced Swords)?
*Kazuuchi* ("quantity-struck") refers to standardized swords produced in large volumes without individual custom orders. They were essentially the industrial products of the sword world—inferior to custom pieces in material quality and finish, but engineered for battlefield utility and sufficient sharpness.
Characteristics of kazuuchi include:
- Standardized dimensions in blade length, curvature, and width
- Omitted or generic signatures (group names or place names rather than individual smiths)
- Less refined polishing and shirasaya compared to custom work
- Prices a fraction of commissioned pieces
Bizen Osafune as a Production Center
Osafune in Bizen Province (modern Okayama Prefecture) was the largest sword production hub of the Sengoku period, a proto-industrial city housing hundreds of smiths. The Osafune lineages (descended from Fukuoka Ichimonji, Nagamitsu, and Kagemitsu) developed specialized division of labor—optimizing steel processing, forging, hardening, and polishing as distinct disciplines.
Arming the Ashigaru
Oda Nobunaga's organized ashigaru infantry corps, equipped with mass-purchased firearms and swords, required large-scale procurement of kazuuchi blades. The spread of mass-produced swords was one of the economic foundations that enabled the larger-scale battles of the Sengoku period.
Custom Orders vs. Mass Production
High-ranking gifts to daimyo and bespoke orders for senior retainers continued to be commissioned from master smiths. In custom orders, the smith and patron negotiated blade length, curvature, and hamon design in detail; completed pieces bore the smith's signature. These works became the "famous swords" sought by later collectors and connoisseurs.
