metalworkJuly 08, 2026

Sakai Uchihamono

Sakai Uchihamono (堺打刃物) is a metalwork craft produced in Sakai City, Osaka City, and surrounding areas of Osaka Prefecture, designated as a Traditional Craft Product by the Minister of Economy, Trade and Industry. The craft encompasses bladed products — most notably kitchen knives (hocho) and scissors (hasami) — made using forging and sharpening techniques developed in the Sakai region. The names "Sakai Hamono" and "Sakai Uchihamono" are registered trademarks of the Sakai Hamono Commerce and Industry Cooperative Association Federation.

History

Iron forging technology is said to have been introduced to Sakai during the 5th century, during the period of kofun (ancient burial mound) construction. From the end of the Heian period, this iron forging tradition was continued through sword manufacturing. A decisive turning point came in 1543, when Portuguese traders introduced firearms and other goods — including tobacco — to Japan through Nanban trade. Tobacco knives for cutting this newly imported crop began to be produced in the Sakai area from around the Tensho era during the Muromachi period. Sakai also gained recognition as a production center for firearms, attracting the attention of powerful figures including Oda Nobunaga.

During the Edo period, the Tokugawa shogunate acknowledged the exceptional quality of Sakai blades and arranged for them to be sold exclusively under the seal "Sakai Goku," distinguishing them from blades produced elsewhere in Japan. In the Genroku era of the mid-Edo period, Sakai blacksmiths further developed kitchen knife varieties including the deba bocho, and the range of knife types that exists today was largely established during this time. This long continuum of ironworking expertise is the foundation upon which contemporary Sakai Uchihamono rests. For broader context on forged blade traditions across Japan, see Echizen Uchihamono: Forged Blades from Fukui and Sanjo Uchihamono: Forged Tools from Niigata.

Techniques & Production Process

The manufacturing process of Sakai Uchihamono is broadly divided into three stages: forging (kaji), sharpening (togi), and handle attachment (e-tsuke). Each stage is carried out by specialist craftsmen operating under a division-of-labor system, rather than a single artisan completing the entire blade.

The forging stage begins with joining two distinct steel materials: jigane (soft iron) and hagane (steel blade metal). The shaped blade then undergoes yakinamashi (annealing), a process of gradual cooling that relieves internal stress. This is followed by yakiire (quenching), in which the blade is heated to between 750 and 800 degrees Celsius and then rapidly cooled in water to harden the steel. The final heat-treatment step is yakimodoshi (tempering), which involves reheating the blade in a furnace to between 160 and 180 degrees Celsius to reduce brittleness.

The sharpening stage includes a step that is unique to Sakai and not practiced in other production regions: the use of a chisel (tagane) to remove subtle warping in the blade. This technique contributes to the precision associated with finished Sakai blades. The process concludes with the handle attachment stage, completing the knife or other bladed instrument. Sakai Uchihamono can be compared with other Japanese forged blade traditions such as Tosa Hamono: Traditional Blades from Kochi and Seki Hamono: Blades from the City of Swords in Gifu, as well as the related scissor tradition of Banshu Hamono: Scissors and Cutlery from Hyogo.

How to Identify Sakai Uchihamono

Sakai Uchihamono blades are produced through the lamination of two materials — jigane (soft iron) and hagane (steel) — in a forge-welded construction, a structural characteristic that distinguishes them from single-material blades. Authentic products may carry markings associated with the registered trademarks "Sakai Hamono" or "Sakai Uchihamono," held by the Sakai Hamono Commerce and Industry Cooperative Association Federation. The distinctive flat-correcting step performed with a tagane chisel during sharpening is a production technique exclusive to the Sakai tradition and not replicated in other blade-making regions of Japan.

The Craft Today

Sakai Uchihamono holds close to 90% of the market share among knives used by professional chefs in Japan, reflecting the enduring regard in which the craft is held within the culinary industry. Production continues in Sakai City and surrounding areas of Osaka Prefecture, organized around the long-established division-of-labor system in which forging, sharpening, and handle attachment are each handled by dedicated specialist craftsmen. The craft is recognized under the national framework for traditional craft industries overseen by the Ministry of Economy, Trade and Industry. Sakai Uchihamono sits within a broader landscape of Japanese metalwork traditions; related crafts include Nanbu Tekki: Iron Casting from Iwate, Takaoka Douki: Cast Bronze Craft from Toyama, Tsubame Tsuiki Douki: Hammered Copper from Niigata, and Osaka Naniwa Pewterwork: Traditional Tin Craft from Osaka. For an overview of the wider field, see Japanese Metalwork: The Complete Guide.

Frequently Asked Questions

What types of products are made as Sakai Uchihamono?

Sakai Uchihamono encompasses bladed products including kitchen knives (hocho) and scissors (hasami). The range of kitchen knife types now associated with the craft was largely established during the Genroku era of the mid-Edo period, when Sakai blacksmiths developed varieties such as the deba bocho.

How is a Sakai Uchihamono knife manufactured?

Production is divided into three specialist stages: forging (kaji), sharpening (togi), and handle attachment (e-tsuke). The forging stage involves joining jigane (soft iron) and hagane (steel), followed by annealing, quenching at 750–800°C, and tempering at 160–180°C. During sharpening, a chisel (tagane) is used to correct subtle warping — a technique unique to Sakai.

What makes Sakai Uchihamono distinct from blades made in other regions?

One distinguishing production feature is the use of a tagane chisel during the sharpening stage to remove subtle warping, a step not practiced in other blade-making regions. Additionally, the Sakai tradition employs a strict division-of-labor system in which forging, sharpening, and handle attachment are each performed by separate specialist craftsmen.

What is the market significance of Sakai Uchihamono?

Sakai Uchihamono holds close to 90% of the market share among knives used by professional chefs in Japan.

Are "Sakai Hamono" and "Sakai Uchihamono" protected names?

Yes. Both "Sakai Hamono" and "Sakai Uchihamono" are registered trademarks held by the Sakai Hamono Commerce and Industry Cooperative Association Federation.